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Mar 8, 2021 • 1h 1min
106. Case Report: A Hole in the HFpEF Diagnosis – Boston University, Massachusetts General Hospital, and Brigham and Women’s Hospital
CardioNerds (Amit Goyal & Karan Desai) join Dr. Alex Pipilas (FIT, Boston University) and Dr. Danny Pipilas (FIT, MGH) for in Boston, MA. Adult congenital heart disease expert Dr. Keri Shafer (Brigham and Women’s Hospital) provides the E-CPR expert segment. They discuss a case of heart failure secondary to sinus venosus defect with partial anomalous pulmonary venous return.
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Jump to: Patient summary – Case media – Case teaching – References
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Patient Summary
A 78-year-old woman with atrial fibrillation and heart failure with preserved ejection fraction presented with recurrent dyspnea and volume overload. A transthoracic echocardiogram demonstrated severe right ventricular enlargement and dysfunction. A CT pulmonary angiogram demonstrated partial anomalous pulmonary venous return and a transesophageal echocardiogram revealed a sinus venosus defect with left to right shunting. A right heart catheterization with oximetry saturation (“shunt run”) demonstrated pulmonary hypertension and a large left to right shunt (Qp/Qs ~ 3). She was referred for cardiac surgery and underwent repair of the sinus venosus defect and baffling of the anomalous pulmonary venous flow to the left atrium.
Case Media
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B
C
Click to Enlarge
A. CXR, B. ECG, C. TR Velocity
TTE: PLAX
TTE: RV Outflow
TTE: AP4
TEE: Sinus Venosus ASD
TEE: Sinus Venosus ASD 2
Episode Schematics & Teaching
Figure 1
Figure 2
Pearls
It is critical to determine whether there is more to a diagnosis of heart failure with a preserved ejection fraction. Utilize all available clinical data and risk calculators to determine if there are more appropriate diagnoses causing the patients symptoms, especially when certain aspects of the presentation does not add up.
Right ventricular failure may be related to pressure overload (i.e., pulmonary hypertension, PV stenosis), volume overload (i.e., tricuspid regurgitation, left to right shunt lesions), or primary myocardial process (i.e., ischemia, infiltration, ARVC). In cases of severe right ventricular enlargement and dysfunction without apparent cause, look for a left to right shunt lesion (i.e., VSD, ASD, PAPVR). Sometimes further imaging (TEE, cardiac CT, cardiac MRI) is necessary to detect these lesions if not visualized on TTE.
Left to right shunts can be quantified in the cardiac catheterization laboratory by measuring oxygen saturation in each chamber and detecting an O2 “step up” (increase in oxygen saturation from one chamber to the next). Large left to right shunts are quantified using the Fick principle and comparing the ratio of pulmonary blood flow (Qp) to systemic blood flow (Qs).
Large left-to-right shunts can cause right ventricular volume overload and pulmonary hypertension. Patients often present with signs and symptoms of right ventricular failure including shortness of breath, exercise intolerance, volume overload, atrial arrhythmias, and recurrent heart failure. Some may develop right-to-left shunting and possible paradoxical embolism.
ACC/AHA guidelines recommend closure of a sinus venosus defect if the PA systolic pressure is < 50% systemic pressures AND PVR is <1/3 of SVR. It is a Class III recommendation (potentially harmful) to close a defect if PA systolic pressure is >2/3 of systemic systolic pressure and/or PVR >2/3 SVR.
Quotable:
About ACHD – “As we go through this physiology, I just want to remind all of the listeners out there that you have the opportunity to apply the knowledge you have from medical school about physiology to the adult human heart. You can’t make assumptions as we sometimes do in the setting of normal cardiac anatomy. We really need to think about the compliances of the downstream structures and where is the blood flow.” – Keri Shafer, MD
Notes
What are features and causes of RV failure?
The clinical symptoms of right ventricular failure include fatigue, dyspnea, lower extremity edema, elevated JVP, early satiety, and abdominal swelling. Although there is overlap between the symptoms of right ventricular failure and left ventricular failure, in isolated right ventricular failure orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema are typically absent.
It is convenient to break down the etiologies of right heart failure into “buckets”. Specifically, volume overload, pressure overload, and primary cardiomyopathic processes. Causes of right ventricular volume overload include valvular disease (tricuspid regurgitation, pulmonic insufficiency) and left-to-right shunts (ASD, VSD, sinus venosus defect, coronary sinus defect, PAPVR). Causes of right ventricular pressure overload, or excessive afterload, include pulmonary arterial hypertension, pulmonary embolism and chronic thromboembolic pulmonary hypertension, pulmonic stenosis, chronic hypoxemia, and longstanding elevated left atrial pressure causing group 2 PH (mitral regurgitation/stenosis, HFrEF, HFpEF). Cardiomyopathic processes include cardiac amyloidosis, right ventricular myocardial infarction, post-transplant right ventricular dysfunction, and arrhythmogenic right ventricular cardiomyopathy. Also, keep in mind that these disease processes often overlap.
2. What is partial anomalous pulmonary venous return (PAPVR)?
Normally, the four pulmonary veins return oxygenated blood to the left atrium.
Partial anomalous pulmonary venous return is a spectrum of congenital heart defects when one or more (but not all) of the pulmonary veins return oxygenated blood from the lungs to the systemic venous system (typically the SVC, IVC, or RA).
The most common PAPVRs are LUPV (left upper pulmonary vein) à ascending vertical vein à innominate vein or RUPV à SVC. The latter is often associated with a concurrent sinus venosus defect connecting the RA and LA.
Scimitar syndrome is a subtype of PAPVR in which part or all of the blood from the right lung is returned into the IVC. On chest X-ray, the outline of the anomalous drainage and associated congestion gives the appearance of a scimitar.
3. What is a sinus venosus defect? What is the sinus venosus?
Early in development, the atria are one single chamber. The sinus venosus is the posterior entryway for blood returning to this primitive atrium.
Eventually, the sinus venosus closes and moves rightward due to hemodynamic shifts during development.
In adults, the sinus venous becomes the smooth posterior wall of the adult right atrium called the sinus venarum and is separated from the anterior wall of the RA by the cristae terminalis.
If a persistent channel through the sinus venosus remains into adulthood, it can result in an intra-cardiac shunt. This is termed a sinus venosus defect and accounts for 10-15% of all inter-atrial shunts.
Typically, this shunt is left-to-right and may lead to right ventricular volume overload, dysfunction and pulmonary hypertension. Some patients may develop right-to-left shunting or paradoxical embolism. Arrhythmias are an important complication.
As above, sinus venosus defects are associated with PAPVR with RUPV à SVC.
NOTE: a sinus venosus defect is NOT a defect in the atrial septum and so is not an “ASD”. Rather it is a defect connecting either the SVC-RA junction (more common) or the IVC-RA junction to the LA. The former is associated with a RUPV PAPVR and the latter is associated with a RLPV PAPVR.
4. What are the imaging modalities that are used to identify sinus venosus defects?
Sinus venosus defects are poorly visualized on transthoracic echocardiography (TTE).
If there is clinical suspicion for an inter-atrial shunt not visualized on TTE, then a transesophageal echocardiogram (TTE) should be performed. Additional imaging modalities include cross-sectional imaging with cardiac CT or cardiac MRI, which may also identify the presence of concomitant PAPVR.
In cases of RV dilation and dysfunction without know etiology, evaluation for sinus venosus defect +/- PAPVR should be pursued.
5. What is the role for right heart catheterization in characterizing shunt defects?
A right heart catheterization is useful for multiple reasons.
Intracardiac pressure measurements serve as a surrogate for volume status.
One can also obtain oxygen saturation in each cardiac chamber to identify the presence of a “step up”, or unexpected increase in oxygen saturation, which signifies a left-to-right shunt. To simplify, a left-to-right shunt is when oxygenated blood from the systemic circulation (left) inappropriately mixes with the pulmonary circulation (right), increasing the oxygen concentration. This can occur via anomalous pulmonary veins, defects at the atrial or ventricular level, or sometimes systemic arterio-venous fistulas.
To obtain pressure measurements, a balloon-tipped catheter (Swann-Ganz catheter, PA catheter) is inserted through a vein and advanced through the heart and “wedged” in the pulmonary artery to estimate left atrial pressure. Normal pressure measurements are as follows (in mmHg): Right atrium < 8, right ventricle 25/5 (systolic/end diastolic pressure), pulmonary artery 25/15 (systolic/diastolic), and pulmonary capillary wedge pressure 8-12. Cardiac output can also be measured by thermodilution and via the Fick principle.
In our case, the patient’s pressure measurements were: RA 20, RV 72/24, PA 68/36 (47), PCWP 26.
As the catheter is passed through the great vessels and cardiac chambers and into the pulmonary artery, small amounts of blood can be sent for oximetry. Blood can be taken from the proximal and distal SVC, proximal and distal IVC, right atrium (low, mid, high), RV, PA and aorta. Taking multiple samples in each chamber are only necessary when the level of a suspected shunt is unknown. A left to right shunt is detected by an oximetry “step up” where oxygenated blood from the systemic circulation blood mixes with deoxygenated blood from the venous circulation.
An oxygen saturation step up of >7% is considered significant at the level of the great veins and RA while a step up of >5% is considered significant at levels distal to the RA.
For intra-cardiac shunts, the degree of left to right shunting can be quantified by calculating the ratio of pulmonary blood flow (Qp; oxygen consumption divided by the difference in AV oxygen content across the lungs) to systemic blood flow (Qs; oxygen consumption divided by the difference in the arteriovenous oxygen content across the systemic circulation). This ratio is calculated using the Fick principle for cardiac output, and by making a few assumptions.
Because intra-cardiac shunts will affect the mixed venous (pulmonary artery oxygen saturation), a systemic mixed venous saturation needs to be calculated to estimate “pre-shunt” mixed venous O2. This is defined by Flamm’s formula: (3*SVC +IVC)/4
We also assume that oxygen consumption, hemoglobin concentration and atmospheric pressure are constant. This allows for many of the terms in the complex calculation to cancel out, leaving only the oximetry saturations.
Ultimately, the simplified equation for Qp/Qs becomes the difference in saturation across the systemic circulation (Ao – calculated mixed venous) divided by the difference across the pulmonic circulation (PV sat – PA sat).
Practically, the pulmonary venous saturation cannot be obtained without transeptal puncture or retrograde catheterization through the left sided valves. In the absence of a significant R to L shunt, we expect systemic arterial saturation and pulmonary venous saturation to be the same, and thus the pulmonary venous saturation is often replaced by systemic arterial saturation in this equation.
Small shunts are defined by Qp/Qs <1.5. These are often asymptomatic and generally do not need to be treated. Large shunts are defined by Qp/Qs >2 and often require closure.
Our patient’s saturations were as follows: SVC 50%, IVC 43%, RA 77%, PA 79%, Ao 94%.
The calculated mixed venous saturation is then 48.25% ((3*50% + 1*43%) / 4 = 48.25%).
Finally, her Qp/Qs = (94 – 48.25)/(94-79) = 3.1.
When we walk through this equation with our patient’s data, her Qp/Qs is 3.1, meaning that for every 1 L of cardiac output through the systemic circulation, 3.1 L are going through the pulmonary circulation.
6. What are the indications and contraindications to correction of sinus venosus defects and PAPVR?
According to the 2018 ACC/AHA guidelines, in adults with a primum ASD, sinus venous defect or coronary sinus defect causing impaired functional capacity, right atrial and/or right ventricular enlargement and net left to right shunt sufficiently large to cause physiological sequelae (Qp/Qs >1.5:1) – without cyanosis at rest or during exercise – should be referred for surgical repair unless precluded by comorbidities.
It is important to evaluate for pulmonary hypertension, as the recommendations differ based on the degree of concomitant pHTN.
Surgical correction is:
Class I (B-NR) if the systolic PA pressure is less than 50% of the systemic pressure and the PVR is less than one third of the SVR.
Class III, or potentially harmful, (C-LD) if the PA systolic pressure is greater than 2/3 of the systemic systolic pressure or if the PVR is greater than 2/3 of the SVR and/or if there exists a right to left shunt.
Those with PA systolic pressures between 50% and 2/3 systemic pressures and PVRs between 1/3 and 2/3 should be considered for repair on a case-by-case basis (Class IIb, our patient in this case).
References
Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2019;139(14). doi:10.1161/cir.0000000000000603. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000603
De Faria Yeh D, Bhatt AB, Gaggin HK, Januzzi JL. Adult Congenital Heart Disease. In: MGH Cardiology Board Review. 2nd ed. Cham: Springer International Publishing; 2021:387-420. https://www.springer.com/gp/book/9783030457914
Askari AT, Messerli AW. In: Cardiovascular Hemodynamics An Introductory Guide. Cham: Springer International Publishing; 2019. https://www.springer.com/gp/book/9783030191306
CardioNerds Case Report Production Team
Karan Desai, MD
Amit Goyal, MD
Daniel Ambinder, MD

Mar 3, 2021 • 1h 6min
105. Narratives in Cardiology: Racial Disparities in Advanced Heart Failure with Dr. Bryan Smith and Dr. Shirlene Obuobi
CardioNerds (Amit Goyal and Daniel Ambinder) join Dr. Bryan Smith (Advanced Heart Failure and Transplant Cardiologist at the University of Chicago) and Dr. Shirlene Obuobi (rising cardiology fellow, CardioNerds ambassador for the University of Chicago, and creator of ShirlyWhirl, M.D.) They discuss the story of a patient with end stage heart failure due to peripartum cardiomyopathy that highlights racial disparities in healthcare and advanced heart failure. They emphasize the importance of providing mentorship for Black and Indigenous People of Color (BIPOC) and share personal stories of their journey to Cardiology. Dr. Andi Shahu joins us to read his AHA blog titled “Let’s Ban the Phrase “Social Issues”: Social Justice and Advanced Heart Failure Therapies”. Audio editing by CardioNerds Academy intern, Pace Wetstein.
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Quotables:
“One of the reasons why I went into Heart Failure is because I connected a lot with these young patients, a lot of these young black men and black women who were terrified of the hospital. As a resident and a fellow I would go talk to them and really understand their fears and where they are coming from. I think a lot of times these patients can be labeled as ‘noncompliant,’ or ‘withdrawn,’ or ‘aggressive,’ but a lot of times you just have to understand where they’re coming from. And I really found that just sitting down to talk to them, and to get to know them, I was able to help get them better, or a lot of them went on to get VADs or transplant. And, to be perfectly honest, I’m in touch with a lot of these patients who I met as a fellow who…I feel are part of my life….You have to meet patients where they are. Meaning you need to text them, interact with them on social media, and really connect with them in a way they understand.” Dr. Bryan Smith (12:10)
“Being black in America means not getting the benefit of doubt. …I can’t help but wonder if unconscious bias among providers is imposing…unreasonable scrutiny on patients of color.” Shirlene (21:15)
“There are many different ways to combat [racial] disparities. As a Heart Failure physician we have these multidisciplinary meetings where we discuss patients for transplant. And I think it’s…important to highlight to our providers that how we discuss patients really matters. Language definitely matters. Heart failure is art in addition to science. …Sometimes when discussing these patients…charged words are used, like ‘withdrawn,’ or ‘aggressive,’ or ‘ghetto’ even. And it’s all coded, racist language. …Part of our responsibility is to educate everyone with implicit bias training….and to make sure we’re able to advocate for patients in the right way.” Dr. Bryan Smith (22:30)
“I’ve felt like I’ve been paying the minority tax…which is doing the necessary but unpaid and frequently seldom recognized labor of mentorship, community engagement, etc, and also of being hyper visible and acting as a symbol…” – Shirlene (24:52)
“It’s really easy when patients are in the hospital to think of them only as patients and forget that they’re people too, and that people are complex, they have complex emotions, they have reactions to things, sometimes those reactions aren’t necessarily what we would think are appropriate for their medical situation, but they’re what make us human.” – Shirlene (9:50)
Notes:
1. What are some of the racial disparities in diagnosis and outcomes of peri-partum cardiomyopathy, and what are some factors that might be contributing to those disparities?
CVD disease is the leading cause of pregnancy-associated mortality in the US. Black and American Indian/ Alaskan Native women are 3-4x more likely to die from a pregnancy-related cause than white women. (1,2)
The incidence of peripartum cardiomyopathy (PPCM) is 4x higher in black women than in white women. Black women may make up to 40% of the cases. (3,4)
Black women with PPCM have lower LVEF at the time of diagnosis, lower rates of recovery of LVEF, higher incidence of mortality and need for LVAD/ transplant. (1,2)
Studies looking for genetic reasons for this disparity have come up short.
Black women are more likely to have comorbid conditions (i.e., gestational HTN, preeclampsia).
2. What is it like taking care of younger patients with LVEF, especially young black patients?
Working in Advanced Heart Failure gives cardiologists the opportunity to work with younger patients due to the prevalence of CMs that present at younger ages.
Younger patients tend to feel more invincible, and to have more distrust of the medical system.
It is important to get to know these patients, meet them where they are, and communicate with them in ways they understand (text, social media).
3. How can we help to break the black patients’ distrust in the medical system?
Understand the history: medicine has historically excluded and abused black patients. (ie. the Tuskegee study withheld treatment from black sharecroppers, gynecological surgery experimentations on black slave women, a legacy of segregation, etc.)
Listen to our patients and try to meet them where they are.
Understand the social determinants of health (SDOH) that may influence their ability to “adhere” to therapy/ appointments (i.e., difficulty finding childcare, employment restrictions)
Partner with community initiatives (i.e., Urban Health Initiative at University of Chicago)
Hire and train members of the community to work in the hospital!
Invest in Pipeline programs and mentorship.
4. Why is diversity in the medicine important?
Concordance of race between providers and patients improves trust, quality of care, and improves patient outcomes! (5)
Black patients are less likely to be referred for catheterization, AICDs, etc., despite our best efforts to provide equitable care.
Language is important! Consider the use of coded language and racially disparate expectations for patients when discussing issues such as transplant candidacy.
Recruit physicians who are interested in disparities research, and make research into disparities a basis for promotion.
5. How do we engage the rest of the cardiology community to be invested in the recruitment and mentorship of underrepresented minorities in medicine (URiMs)?
URiMs frequently pay the “minority tax,” or the necessary but unpaid and seldom recognized labor of mentorship, community engagement, etc. That can be a heavy load to carry, especially considering only 5% of cardiology fellows identify as being Black.
“You can’t really be what you can’t see” – there’s a responsibility that URMs have in cardiology to be visible to inspire future generations.
However, mentorship of URiMs should not be limited to only URiM faculty. Centers should try to recruit and establish a culture that values diversity.
Diversity shouldn’t be limited to just attributes like race/ gender, but also in interest. Without diversity of thought, you may not have adequate mentorship and community engagement.
Show notes updated as of 3.2.2021
CardioNerds Narratives in Cardiology
The CardioNerds Narratives in Cardiology series features cardiovascular faculty representing diverse backgrounds, subspecialties, career stages, and career paths. Discussing why these faculty chose careers in cardiology and their passion for their work are essential components to inspiring interest in the field.
Each talk will feature a cardiology faculty from an underrepresented group, within at least one of several domains: gender, race, ethnicity, religion, national origin, international graduate status, disadvantaged backgrounds, etc.
Featured faculty will also represent a variety of practice settings, academic ranks, subspecialties (e.g. clinical cardiology, interventional cardiology, electrophysiology, etc), and career paths (e.g. division chief, journal editor, society leadership, industry consultant, etc).
Faculty will be interviewed by fellows-in-training for a two-part discussion that will focus on:
1) Faculty’s content area of expertise2) Faculty’s personal and professional narrative
As part of their narrative, faculty will discuss their unique path to cardiology and their current professional role with particular attention to challenges, successes, and advice for junior trainees. Specific topics will be guided by values relevant to trainees, including issues related to mentorship, work-life integration, and family planning.
To help guide this important initiative, the CardioNerds Narratives Council was founded to provide mentorship and guidance in producing the Narratives series with regards to guests and content. The CardioNerds Narratives Council members include: Dr. Pamela Douglas, Dr. Nosheen Reza, Dr. Martha Gulati, Dr. Quinn Capers, IV, Dr. Ann Marie Navar, Dr. Ki Park, Dr. Bob Harrington, Dr. Sharonne Hayes, and Dr. Michelle Albert.
The Narratives Council includes three FIT advisors who will lead the CardioNerds’ diversity and inclusion efforts, including the current project: Dr. Zarina Sharalaya, Dr. Norrisa Haynes, and Dr. Pablo Sanchez.
Guest Profiles
Dr. Bryan Smith
Dr. Bryan Smith is an Advanced Heart Failure and Transplant Cardiologist at University of Chicago. Dr. Smith completed his medical school training, residency and Cardiology fellowship at University of Chicago, then traversed Lake Shore Drive to complete his advanced HF fellowship at Northwestern. At University of Chicago, he serves as the director of the hemodynamic Cath lab, on the Chicago board for AHA, and as a faculty mentor for SNMA (Student National Medical Association.) Dr. Smith’s interests lie in community-based interventions for heart failure management and racial disparities, and he is the face of several mentorship programs, including the Heart and Vascular Mentoring program here in Chicago.
Shirlene Obuobi, MD
Shirlene Obuobi, M.D. is a current PGY3 IM resident and rising cardiology fellow. Born in Accra, Ghana and bred in Chicago, Hot Springs, Arkansas, and The Woodlands, Texas, Shirlene completed her medical school training at University of Chicago Pritzker School of Medicine, and has remained at the University ever since. She is passionate about narrative medicine, health equity, and health disparities, and espouses these passions via her medical comic platform, ShirlyWhirl, M.D. Outside of medicine, she also loves to write. Within Cardiology, she is most interested in Prevention, but is remaining open minded.
Andi Shahu, MD, MHS
Dr. Andi Shahu is a resident physician in the Osler Medical Residency in Internal Medicine at Johns Hopkins Hospital in Baltimore, MD. He will begin General Cardiology fellowship in July 2021 at Yale University. He is interested in the intersection between cardiovascular outcomes, health equity and health policy. You can follow him on Twitter @andishahu.
References
Irizarry OC, Levine LD, Lewey J, et al. Comparison of Clinical Characteristics and Outcomes of Peripartum Cardiomyopathy Between African American and Non-African American Women. JAMA Cardiol. 2017;2(11):1256-1260. doi:10.1001/jamacardio.2017.3574 (https://jamanetwork.com/journals/jamacardiology/fullarticle/2657313)
DeFilippis EM, Truby LK, Garan AR, et al. Sex-Related Differences in Use and Outcomes of Left Ventricular Assist Devices as Bridge to Transplantation. JACC Heart Fail. 2019;7(3):250-257. doi:10.1016/j.jchf.2019.01.008 https://pubmed.ncbi.nlm.nih.gov/30819381/
Arany Z, Elkayam U. Peripartum Cardiomyopathy. Circulation. 2016;133(14):1397-1409. doi:10.1161/CIRCULATIONAHA.115.020491 (https://pubmed.ncbi.nlm.nih.gov/27045128/)
Lewey J, Levine LD, Elovitz MA, Irizarry OC, Arany Z. Importance of Early Diagnosis in Peripartum Cardiomyopathy. Hypertension. 2020;75(1):91-97. doi:10.1161/HYPERTENSIONAHA.119.13291 (https://pubmed.ncbi.nlm.nih.gov/31707840/0)
Jetty A, Jabbarpour Y, Pollack J, Huerto R, Woo S, Petterson S. Patient-Physician Racial Concordance Associated with Improved Healthcare Use and Lower Healthcare Expenditures in Minority Populations [published online ahead of print, 2021 Jan 5]. J Racial Ethn Health Disparities. 2021;10.1007/s40615-020-00930-4. doi:10.1007/s40615-020-00930-4 (https://pubmed.ncbi.nlm.nih.gov/33403653/)
Takeshita J, Wang S, Loren AW, et al. Association of Racial/Ethnic and Gender Concordance Between Patients and Physicians With Patient Experience Ratings. JAMA Netw Open. 2020;3(11):e2024583. Published 2020 Nov 2. doi:10.1001/jamanetworkopen.2020.24583 (https://pubmed.ncbi.nlm.nih.gov/33165609/)
Amit Goyal, MD
Daniel Ambinder, MD
Pace Wetstein

Mar 1, 2021 • 23min
104. Nuclear and Multimodality Imaging: Anomalous Coronary Arteries & Myocardial Bridges
CardioNerd Amit Goyal is joined by Dr. Erika Hutt (Cleveland Clinic general cardiology fellow), Dr. Aldo Schenone (Brigham and Women’s advanced cardiovascular imaging fellow), and Dr. Wael Jaber (Cleveland Clinic cardiovascular imaging staff and co-founder of Cardiac Imaging Agora) to discuss nuclear and complimentary multimodality cardiovascular imaging for the evaluation of abnormal coronary anatomy including anomalous coronary arteries and myocardial bridges. Show notes were created by Dr. Hussain Khalid (University of Florida general cardiology fellow and CardioNerds Academy fellow in House Thomas). To learn more about multimodality cardiovascular imaging, check out Cardiac Imaging Agora!
Collect free CME/MOC credit just for enjoying this episode!
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Show Notes & Take Home Pearls
Five Take Home Pearls
Anomalous coronaries are present in 1-6% of the general population and predominantly involve origins of the right coronary artery (RCA). Anomalous origination of the left coronary artery from the right sinus, although less common, is consistently associated with sudden cardiac death, especially if there is an intramural course. Sudden cardiac death can occur due to several proposed mechanisms: (1) intramural segments pass between the aorta and pulmonary artery making them susceptible to compression as the great vessels dilate during strenuous exercise; (2) an acute angle takeoff of the anomalous coronary can create a “slit-like” ostium making it vulnerable to closure. Anomalous left circumflex arteries are virtually always benign because the path taken behind the great vessels to reach the lateral wall prevents vessel compression.
Myocardial bridging (MB) is a congenital anomaly in which a segment of the coronary artery (most commonly, the mid-left anterior descending artery [LAD]) takes an intramuscular course and is “tunneled” under a “bridge” of overlying myocardium. In the vast majority of cases, these are benign. However, a MB >2 mm in depth, >20 mm in length, and a vessel that is totally encased under the myocardium are more likely to be of clinical significance, especially if there is myocardial oxygen supply-demand mismatch such as with tachycardia (reduced diastolic filling time), decreased transmural perfusion gradient (e.g. in myocardial hypertrophy and/or diastolic dysfunction), and endothelial dysfunction resulting in vasospasm.
PET offers many benefits over SPECT in functional assessment of MB including the ability to acquire images at peak stress when using dobutamine stress-PET, enhanced spatial resolution, and quantification of absolute myocardial blood flow. For pharmacologic stress in evaluation of MB, we should preferentially use dobutamine over vasodilator stress. Its inotropic and chronotropic effects enhance systolic compression of the vessel, better targeting the pathological mechanisms in pearl 2 above that predispose a MB to being clinically significant.
CCTA can help better define the anatomy of MB as well as anomalous origination of the coronary artery from the opposite sinus (ACAOS), help with risk stratification, and assist with surgical planning.
Instantaneous wave-free ratio (iFR) measures intracoronary pressure of MB during the diastolic “wave-free” period – the period in the cardiac cycle when microvascular resistance is stable and minimized allowing the highest blood flow. This allows a more accurate assessment of a functionally significant dynamic stenosis than fractional flow reserve (FFR) – which can be falsely normal due to systolic overshooting.
Detailed Show Notes
What are some examples of abnormal coronary anatomies and how often do they lead to clinical events?
Abnormal coronary anatomy can relate to the origin (e.g. anomalous origination of coronary artery from the opposite sinus [ACAOS]), course (e.g. myocardial bridging [MB]), intrinsic properties (e.g. aneurysm or hypoplasia), or termination (e.g. fistula) of the coronary artery. In this episode and in these notes, we examine MB and ACAOS in more detail. For an excellent case discussion of anomalous left coronary artery from the pulmonary artery (ALCAPA) by the team from Massachusetts General Hospital, listen to CardioNerds Podcast Episode 81!
MB –Myocardial Bridging
MB is a congenital anomaly in which a segment of the coronary artery (most commonly, the mid-left anterior descending artery [LAD]) takes an intramuscular course and is “tunneled” under a “bridge” of overlying myocardium.
MB was originally identified at autopsy by Reyman in his dissertation, “Disertatio de vasis cordis propriis “ in 1737. In the largest subsequent autopsy study by Risse et al. involving 1056 patients, MB was demonstrated in 26% of patients.
Because it is so prevalent, it is difficult to determine its clinical significance. In most patients, MB is an incidental finding with an excellent survival rate (97% at 5 years); however, there are associations with myocardial ischemia, infarction, stress cardiomyopathy, arrhythmia, and sudden cardiac death (SCD).
MB can generally be classified into two subtypes: a “superficial” variant which represents 75% of cases and a “deep” variant in which the LAD deviates towards the right ventricle (RV) and dives into the intraventricular septum. The overlying muscle bundle in the deep variant is typically at an oblique or transverse angle resulting in twisting of the tunneled segment and more commonly compromised coronary flow.
One of the longest MB usually occurs in association with ACAOS! In this case, the left coronary artery comes off the right coronary cusp. The Left Main (LM) is around 3-4x longer in this instance and dives into the interventricular septum and takes a trans-septal course behind the pulmonary artery before emerging on the other side.
There is increased prevalence in certain patient populations: hypertrophic cardiomyopathy (HCM), patients with spontaneous coronary artery dissection (SCAD) +/- fibromuscular dysplasia (FMD), and heart transplant recipients
ACAOS – anomalous origination of coronary artery from the opposite sinus
Anomalous coronaries are present in 1-6% of the general population and predominantly involve the origin of the right coronary artery (RCA)
Anomalous origination of the left coronary artery from the right sinus, although less common, is consistently related to SCD. Separate studies have shown the incidence of SCD may be as high as 23% or 59% of cases in athletes under the age of 20 years.
In a large Armed Forces Institute of Pathology (AFIP) study of 6.3 million military recruits, the autopsies of recruits who suffered nontraumatic deaths over a 25-year period were reviewed and ACAOS was found to be the most common cause. It accounted for 33% (64 of 126) of nontraumatic deaths and all cases involved a left coronary artery with an interarterial course.
What features predispose MB or ACAOS to become clinically significant? What is the pathophysiology behind development of ischemia in those with clinically significant MB or ACAOS?
MB – myocardial bridging
Given the majority of MB is benign, correlating MB as causative in myocardial ischemia and its consequences has been a diagnostic challenge.
In systole, the portion of the artery that is tunneled under the MB (bridge segment) is compressed. This can manifest clinically as angina, acute coronary syndrome, left ventricular (LV) dysfunction, arrhythmias, and SCD. However, the majority of myocardial perfusion occurs in diastole which is why MB is usually benign. Nonetheless, certain conditions in patients with MB can set up an oxygen supply-demand mismatch severe enough to lead to myocardial ischemia:
Exercise-related stress leads to tachycardia which can decrease diastolic filling time for the coronary arteries and lead to more of the cardiac cycle to be spent in systole
Myocardial hypertrophy and diastolic dysfunction can affect the transmural perfusion gradient increasing supply-demand mismatch. Furthermore, LV hypertrophy can compress the microvasculature and reduce the microvascular reserve.
Endothelial dysfunction (driven by metabolic changes secondary to hypoxia) can contribute to coronary compression and lead to the development of accelerated atherosclerosis and/or coronary vasospasm (leading to compression of the epicardial coronary artery throughout the cardiac cycle, not just during systole)
There has been a recognized multiplier-effect described by Klues et al. in which the greater the degree of systolic narrowing of the MB, the greater the reduction in diastolic vessel diameter. This is also associated with increased retrograde flow in the coronary artery (which not only reduces perfusion but can introduce shear wall stress and predispose to plaque formation) and reduced flow reserve.
Myocardial ischemia can also occur due to “branch steal.” The LAD may have septal perforators that arise from the tunneled segment. When there is compression of the vessel under the MB, there can be “steal” from these septal branches due to the Venturi effect. The septal branches are essentially depressurized because as the vessel narrows, velocity increases but the fluid (coronary blood flow) exerts less pressure. Thus, mild to moderate MB severity typically demonstrates septal ischemia (due to branch steal) rather than distal ischemia downstream from the compression.
The vessel segment proximal to the bridge appears to develop atherosclerosis at increased rates approaching 90% — likely as the sequela of shear stress. In contrast, the tunneled segment of the artery is usually spared of atherosclerosis because:
The intima is significantly thinner with a higher prevalence of contractile cells (thought to be negatively associated with development of atherosclerotic lesions)
There is a lack of foam cells (lipid-laden macrophages that are important components of atherosclerosis)
There is reduced expression of known vasoactive agents such as nitric oxide synthase, endothelin-1, and angiotensin-converting enzyme
ACAOS – anomalous origination of coronary artery from the opposite sinus
The mechanism of ischemia for ACAOS with an interarterial course (between the pulmonary artery and the aorta) and specifically an intramural course has not fully been determined. An intramural course refers to the proximal part of the epicardial coronary artery being contained within the aortic wall and sharing the aortic wall media without a separating adventitia. There are several proposed mechanisms for why this anatomic setup can lead to myocardial ischemia.
Compression of the vessel between the aorta and the pulmonary artery during intense exercise as the great vessels dilate
The pulmonary artery likely needs to be enlarged secondary to concomitant pulmonary hypertension for this to occur
An anomalous left circumflex is almost never clinically significant because the path it takes behind the great vessels to reach the lateral wall means the vessel is not exposed to compression!
Anacute angle takeoff of the coronary artery, which shares a common wall with the aorta, can result in a significantly narrowed coronary artery ostium (e.g., “slit-like”). This is even further narrowed during exercise when the great vessels expand.
Marked narrowing of the intramural segment due to hypoplasia of the intramural segment
What is the role of nuclear imaging in the evaluation of MB or ACAOS?
MB – myocardial bridging
In general, nuclear imaging evaluation of MB has had mixed results, and available studies generally have smaller sample sizes and most are retrospective. Prior studies — predominantly involving exercise SPECT — have shown that reversible ischemia may be present in patients with MB and systolic compression of the vessel >50% or >75%. However, other studies in similar populations have shown that reversible ischemia was not inducible in patients with MB with similar degrees of systolic compression of the vessel. There are very few studies available assessing the utility of PET stress testing in patients with MB. One prior study demonstrated that PET stress testing revealed decreased myocardial perfusion reserve in patients with MB, although this was with adenosine rather than dobutamine stress (more on this below).
In patients who are symptomatic and have full encasement of the epicardial artery or a deep course seen on coronary CTA, it is reasonable to pursue functional testing, either noninvasive or invasive. Otherwise, we shouldn’t pursue functional testing as the overwhelming majority of MB are benign.
Rest/Stress myocardial perfusion imaging with PET has certain advantages over SPECT:
Improved spatial resolution
Ability to acquire stress images at peak stress if using dobutamine (versus lag time with SPECT)
Absolute myocardial blood flow quantification with PET (not available with SPECT where perfusion is relative)
With PET we can use either Rubidium-82 (half-life = 76 sec) or N-13 Ammonia (half-life = 10 min) as tracers to assess myocardial perfusion. If using dobutamine as the stress agent, either tracer can be injected at peak stress for the stress imaging. However, if we are using exercise as the stress agent, the patient must be transferred from the treadmill to the camera for stress image acquisition. Because of the time it takes to transfer, Rb-82 cannot be used for exercise PET; it’s half-life is so short (76 sec), it will be gone by the time images are acquired! Therefore, if using exercise PET, you must use N-13 Ammonia PET.
When picking a stress agent, remember the goal is to look for significant mechanical compression that leads to coronary ischemia. Therefore, a vasodilator (e.g., adenosine or regadenoson) would be inappropriate. Rather we need to increase chronotropy and inotropy to simulate mechanical compression and can use either dobutamine or exercise.
NOTE – If the patient has a resting significant mid ventricular or left ventricular outflow gradient (as occasionally seen in HCM) and/or is pacer-dependent, dobutamine and exercise may increase the LVOT gradient and compromise hemodynamics. Rather, consider rapid atrial pacing or other pharmacologic stress in these patients.
Dobutamine or exercise echocardiography are alternatives to nuclear imaging.
Since MB is often studied in younger patients and since younger patients generally have rapid heart rate recovery, if using exercise as a stressor, consider supine bicycle rather than treadmill so that stress TTE images may be acquired prior to HR recovery for increased sensitivity.
ACAOS – anomalous origination of coronary artery from the opposite sinus
The 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease state that in patients w/ ACAOS with either left coronary artery arising from the right sinus or right coronary artery arising from the left sinus, ischemic symptoms or ischemia during functional testing is a Class I indication for surgery.
After identification of ACAOS, it is reasonable to consider functional testing with nuclear imaging, however the sensitivity of this approach is not yet known. Also, the intense physical exertion that usually results in SCD in these patients is usually not achieve with standard stress tests, so the sensitivity of these tests are difficult to judge. The risks/benefits of functional nuclear imaging should be addressed with patients in shared decision making with the patient.
A number of case reports have described inducible ischemia on myocardial perfusion imaging in patients with ACAOS. This may provide additional justification for surgical intervention.
Dr. Wael Jaber (our excellent podcast expert guest on this episode!) as part of the group with Cremer et al. demonstrated in a retrospective study of 27 patients with anomalous take-off of the RCA from the left coronary sinus (AAORCA) that patients with typical angina and exertional dyspnea had a significantly higher rate of demonstrable ischemia on an exercise N13-ammonia positron emission tomography (PET) protocol compared to patients without symptoms. The large majority (11/12) of the patients who underwent surgery had demonstrable ischemia on the above protocol. There were no deaths at 245 days in either the conservative management group or those who underwent surgery. Evidence of ischemia on exercise N13-ammonia positron emission tomography (PET) protocol in patients with may identify patients with AAORCA who would benefit from surgical vs. conservative management.
What is the role of coronary CTA (CCTA) in the evaluation of MB or ACAOS?
Cross-sectional imaging with CCTA is crucial in the assessment of MB and ACAOS for both identifying the abnormality and risk stratification.
MB – myocardial bridging
CCTA has increased the detection of MB from ~5% on invasive coronary angiography to ~21% – much closer to what has been identified on autopsy studies.
CCTA can help risk stratify by:
Quantifying the depth (>2mm considered clinically significant)
Quantifying the length (>20 mm considered clinically significant)
Observing the degree of encasement (more fully encased considered clinically significant)
Detect concurrent atherosclerosis (particularly proximal to the MB)
If there are high risk features and corrective surgery is planned, the anatomical information provided by the CCTA is useful for surgical planning. NOTE – If depth >5 mm and/or length >25 mm, CABG is preferred over myotomy as risks of myotomy is considerable in these circumstances!
ACAOS – anomalous origination of coronary artery from the opposite sinus
CCTA is endorsed by the European Society of Cardiology (ESC) as the first-line diagnostic imaging in known or suspected coronary artery anomalies. The American Heart Association (AHA) Committee on Cardiovascular Imaging provides a IIa recommendation for CCTA or MRI in the evaluation of anomalous coronary arteries.
CCTA can help risk stratify patients by identifying anatomic features that confer a higher risk of SCD:
Slit-like orifice of the coronary ostium
Acute angle of origin
Intramural segment: identification of an intramural segment is physiologically important (as discussed above), but also guides treatment. These patients can be potentially treated by coronary unroofing, unlikepatients with intraarterial course and no intramural segment
Some general considerations for CCTA evaluation:
Low heart rate is needed to optimize image quality. We commonly accomplish this by giving beta blocker and/or ivabridine.
Consider strategies to minimize radiation exposure as able (e.g., in ACAOS we can use prospective gating in which we choose only to image in a certain prespecified phase of the cardiac cycle rather than the whole cardiac cycle as done in retrospective gating)
To avoid radiation exposure and iodinated contrast administration with CCTA, cardiac MRI can be considered
Additionally, you can obtain concomitant assessment of ventricular size, function, shunt, perfusion, and viability
This comes at the expense of decreased spatial resolution, long examination time necessitating significant patient cooperation, and artifact and incompatibility (sometimes prohibitive) from pacemaker or other metallic implants
What is the role of left heart catheterization in the evaluation of MB and ACAOS?
MB – myocardial bridging
Coronary angiography is useful for identifying MB, but is less sensitive than CCTA. Altogether, MB identified by coronary angiography may be more severe than those identified by CCTA, as the mechanical compression must be severe enough to be noticed angiographically. However, a majority of even these bridges have a benign natural history. Therefore, additional risk stratification may be obtained invasively to understand the functional significance of a MB. This can be obtained by combining invasive coronary angiography with tools such as instantaneous wave-free ratio (iFR) and intravascular ultrasound (IVUS).
Fractional flow reserve (FFR) is the gold-standard for invasive assessment of intermediate fixed coronary stenoses and correlates with outcomes. iFR has been shown to be non-inferior to FFR.
However, FFR has not been validated in the assessment of dynamic compression, as with myocardial bridging. In dynamic compression, iFR offers some notable advantages over FFR:
In FFR we are checking the average of the blood pressure and flow over the whole cardiac cycle — systole and diastole. Because of systolic compression in MB, there is a spurious increase in the intracoronary systolic pressure that may yield a falsely normal FFR value — this is known as systolic pressure overshooting
In iFR, on the other hand, we are measuring intracoronary pressure during the diastolic “wave free” period — the period in the cardiac cycle when microvascular resistance is stable and minimized allowing the highest blood flow. This gives a more accurate assessment of functionally significant dynamic stenosis
iFR is considered positive if it is < 0.89. The grey zone in iFR studies is >0.86 and <0.93, so ideally, we want < 0.86 for a more definitive true positive.
Pre- and post-invasive intervention with dobutamine stress iFR testing in addition to relief of symptoms can help guide when to recommend to patients to return to exercise after an invasive intervention on the MB. IVUS imaging shows a highly specific “Half Moon” sign associated with MB—it is unclear why this happens. We can utilize assistance of provocative testing (dobutamine, acetylcholine, rapid A-pacing) to further assess the change in the vessel structure under stress
The Myocardial Bridge Study, led by Dr. Joanna Ghobrial, is an ongoing prospective study looking to correlate functional testing of MB (invasive and non-invasive) and long-term clinical outcomes.
ACAOS – anomalous origination of coronary artery from the opposite sinus
Similar to in MB, iFR and IVUS are emerging tools utilized to help risk stratify patients with ACAOS
IVUS with concurrent dobutamine stress testing can allow for dynamic assessment of anomalous coronary arteries both at rest and under stress. The effects of physiologicor pharmacological stress on the morphology of the intramural segment of an interarterial coronary can provide additionaldata to guide which patients may warrant surgery – particularly patients with anomalous take-off of the right coronary artery from the left coronary sinus (in which surgical intervention is more controversial).
Guest Profiles
Wael Jaber, MD
Wael Jaber, MD, is a staff cardiologist in the Section of Cardiovascular Imaging, Robert and Suzanne Tomsich Department of Cardiovascular Medicine, at the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic. Dr. Jaber specializes in cardiac imaging (both nuclear cardiology and echocardiography) and valvular heart disease. Dr. Jaber attended college at the American University in Beirut, graduating with a Bachelor of Science in biology. He then went on at the American University to receive his medical degree while making the Dean’s honor list. He completed his residency in internal medicine at the St. Luke’s-Roosevelt Hospital Center at Columbia University College of Physicians and Surgeons, where he also completed fellowships in cardiovascular medicine and nuclear cardiology. Dr. Jaber is currently is the Medical Director of the Nuclear Lab and of the Cardiovascular Imaging Core Laboratory in C5Research. He is fluent in English, French and Arabic. He is the author of Nuclear Cardiology review: A Self-Assessment Tool and cofounder of Cardiac Imaging Agora.
Dr. Aldo L Schenone
Dr. Aldo L Schenone is one of the current Chief Non-Invasive Cardiovascular Imaging Fellows at the Brigham and Women’s Hospital. He completed medical school at the University of Carabobo in Valencia, Venezuela, and then completed both his Internal Medicine residency and Cardiology fellowship at the Cleveland Clinic where he also served as a Chief Internal Medicine Resident.
Dr. Erica Hutt
Dr. Erika Hutt @erikahuttce is a cardiology fellow at the Cleveland Clinic. Erika was born and raised in Costa Rica, where she received her MD degree at Universidad de Costa Rica. She then decided to pursue further medical training in the United States, with the goal of becoming a cardiologist. She completed her residency training at Cleveland Clinic and went on to fellowship at the same institution. Her passions include infiltrative heart disease, atrial fibrillation, valvular heart disease and echocardiography among many. She is looking forward to a career in advanced cardiovascular imaging.
References and Links
1. Agarwal PP, Dennie C, Pena E, et al. Anomalous Coronary Arteries That Need Intervention: Review of Pre- and Postoperative Imaging Appearances. Radiographics. 2017 May-Jun 2017;37(3):740-757.
2. Angelini P, Villason S, Chan AV, et al. Normal and anomalous coronary arteries in humans.In: Angelini P, ed. Coronary Artery Anomalies: A Comprehensive Approach. Philadelphia: Lippincott Williams & Wilkins; 1999:27–150.
3. Angelni P, Velasco JA, Flamm S. Coronary anomalies: incidence, pathophysiology, and clinical relevance. Circulation. 2002;105:2449-2454.
4. Admin CL. Return to Play and Sports Cardiology. In: Clinic C, ed. Tall Rounds2020: http://consultqdlive.mediaspace.kaltura.com/media/t/0_ivale2zp/75663251..
5. Cremer PC, Mentias A, Koneru S, et al. Risk stratification with exercise N(13)-ammonia PET in adults with anomalous right coronary arteries. Open Heart. 2016 2016;3(2):e000490.
6. Davies JE, Sen S, Dehbi HM, Al-Lamee R, Petraco R, Nijjer SS, Bhindi R, Lehman SJ, Walters D, Sapontis J, Janssens L, Vrints CJ, Khashaba A, Laine M, Van Belle E, Krackhardt F, Bojara W, Going O, Härle T, Indolfi C, Niccoli G, Ribichini F, Tanaka N, Yokoi H, Takashima H, Kikuta Y, Erglis A, Vinhas H, Canas Silva P, Baptista SB, Alghamdi A, Hellig F, Koo BK, Nam CW, Shin ES, Doh JH, Brugaletta S, Alegria-Barrero E, Meuwissen M, Piek JJ, van Royen N, Sezer M, Di Mario C, Gerber RT, Malik IS, Sharp ASP, Talwar S, Tang K, Samady H, Altman J, Seto AH, Singh J, Jeremias A, Matsuo H, Kharbanda RK, Patel MR, Serruys P, Escaned J. Use of the instantaneous wave-free ratio or fractional flow reserve in PCI.N Engl J Med. 2017; 376:1824–1834.
7. Erbel R, Rupprecht H-J, Ge J, Gerber T, Görge G, Meyer J. Coronary artery shape and flow changes induced by myocardial bridging: assessment by intravascular ultrasound. Echocardiography 1993;10:71–7.
8. Escaned J, Cortés J, Flores A, et al. Importance of diastolic fractional flow reserve and dobutamine challenge in physiologic assessment of myocardial bridging. J Am Coll Cardiol 2003;42:226–33.
9. Gawor R, Kuśmierek J, Płachcińska A, et al. Myocardial perfusion GSPECT imaging in patients with myocardial bridging. J Nucl Cardiol. Dec 2011;18(6):1059-1065.
10. Götberg M, Christiansen EH, Gudmundsdottir IJ, Sandhall L, Danielewicz M, Jakobsen L, Olsson SE, Öhagen P, Olsson H, Omerovic E, Calais F, Lindroos P, Maeng M, Tödt T, Venetsanos D, James SK, Kåregren A, Nilsson M, Carlsson J, Hauer D, Jensen J, Karlsson AC, Panayi G, Erlinge D, Fröbert O; iFR-SWEDEHEART Investigators. Instantaneous wave-free ratio versus fractional flow reserve to guide PCI.N Engl J Med. 2017; 376:1813–1823
11. Hakeem A, Cilingiroglu M, Leesar MA. Hemodynamic and intravascular ultrasound assessment of myocardial bridging: fractional flow reserve paradox with dobutamine versus adenosine. Catheter Cardiovasc Interv 2010;75:229–36.
12. IGe J, Erbel R, Rupprecht HJ, et al. Comparison of intravascular ultrasound and angiography in the assessment of myocardial bridging. Circulation 1994;89:1725–32.
13. Kanwal A, Sha AB. Myocardial Bridging in Adults. 2020. https://www.acc.org/latest-in-cardiology/articles/2020/08/04/08/48/myocardial-bridging-in-adults.
14. McCray LC, Fogwe DT, Aggarwal K, Karuparthi PR. Novel Assessment of Ischemia in Patients With Anomalous Right Coronary Artery. JACC: Case Reports. 2019;1(5):819-822.
15. Lee MS, Chen C-H. Myocardial bridging: an up-to-date review. J Invasive Cardiol 2015;27:521–8.
16. Lim JC, Beale A, Ramcharitar S, Medscape. Anomalous origination of a coronary artery from the opposite sinus. Nat Rev Cardiol. Oct 2011;8(12):706-719.
17. Lin S, Tremmel JA, Yamada R, et al. A novel stress echocardiography pattern for myocardial bridge with invasive structural and hemodynamic correlation. J Am Heart Assoc. Apr 2013;2(2):e000097.
18. Monroy-Gonzalez AG, Alexanderson-Rosas E, Prakken NHJ, et al. Myocardial bridging of the left anterior descending coronary artery is associated with reduced myocardial perfusion reserve: a. Int J Cardiovasc Imaging. Feb 2019;35(2):375-382.
19. Sen S, Asrress KN, Nijjer S, Petraco R, Malik IS, Foale RA, Mikhail GW, Foin N, Broyd C, Hadjiloizou N, Sethi A, Al-Bustami M, Hackett D, Khan MA, Khawaja MZ, Baker CS, Bellamy M, Parker KH, Hughes AD, Francis DP, Mayet J, Di Mario C, Escaned J, Redwood S, Davies JE. Diagnostic classification of the instantaneous wave-free ratio is equivalent to fractional flow reserve and is not improved with adenosine administration. Results of CLARIFY (Classification Accuracy of Pressure-Only Ratios Against Indices Using Flow Study).J Am Coll Cardiol. 2013; 61:1409–1420
20. Stout KK, Daniels CJ, Aboulhosn JA, et al.2018 ACC/AHA Guideline for the managementof adults with congenital heart disease: AReport of the American College of Cardiology/American Heart Association Task Force onClinical Practice Guidelines. Circulation 2019;139:e698–800
21. Tarantini G, Barioli A, Nai Fovino L, et al. Unmasking Myocardial Bridge-Related Ischemia by Intracoronary Functional Evaluation. Circ Cardiovasc Interv. 06 2018;11(6):e006247.
22. Tarantini G, Migliore F, Cademartiri F, Fraccaro C, Iliceto S. Left Anterior Descending Artery Myocardial Bridging: A Clinical Approach. J Am Coll Cardiol. Dec 2016;68(25):2887-2899.
23. Uusitalo V, Saraste A, Knuuti J. Multimodality Imaging in the Assessment of the Physiological Significance of Myocardial Bridging. Curr Cardiol Rep. Jan 2016;18(1):2.
Wael Jaber, MD
Dr. Aldo L Schenone
Dr. Erika Hutt
Dr. Hussain Khalid
Amit Goyal, MD

Feb 22, 2021 • 52min
103. Case Report: A Rare Cause of Postpartum Angina and Arrest – University of Maryland
CardioNerds (Amit Goyal & Daniel Ambinder) join University of Maryland cardiology fellows (Manu Mysore, Adam Zviman, and Scott Butler) for some cardiology and an Orioles game in Baltimore! They discuss a rare cause of postpartum angina and cardiac arrest due to coronary vasculitis. Program director Dr. Mukta Srivastava provides the E-CPR expert segment and a message for applicants. Episode notes were developed by Johns Hopkins internal medicine resident Rick Ferraro with mentorship from University of Maryland cardiology fellow Karan Desai.
This case has been published in JACC Case Reports!
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Jump to: Patient summary – Case media – Case teaching – References
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Patient Summary
A woman in her early 30s with a past medical history of Hashimoto’s thyroiditis and one prior miscarriage at <8 weeks presented with chest pain about 6 weeks postpartum from the birth of her third child. In the ED, she continued to report intermittent sharp chest discomfort and found to have a diastolic decrescendo murmur at the left upper sternal border and labs demonstrating a troponin-I of 0.07 ng/dL. Join the UMD Cardionerds for the incredible course and story of this young patient as we go through the differentia and approach to postpartum chest pain and ultimately arrive in a very rare diagnosis! For a detailed course, enjoy the JACC case report.
Case Media
Visit the JACC Case Reports to review the case media!
Episode Schematics & Teaching
The CardioNerds 5! – 5 major takeaways from the #CNCR case
1. How Do We Evaluate Chest Pain in Younger Patients
Start with the same things as everyone else! Think broadly about the big three concerning etiologies of chest pain: Cardiac, Gastric, and Pulmonary (The excellent Clinical Problems Solvers 4+2+2 construct here is always a great resource. Find them at: https://clinicalproblemsolving.com/dx-schema-chest-pain/).
Of course it is important to think about non-life threatening etiologies as well – esophageal spasm, gastric ulcer, rib fracture, skin lesion, among many others – given that high-risk chest pain is less likely in younger adults.
While less common, acute coronary syndrome is not uncommon in young patients, as 23% of patients with MI present at age <55 years.
2. What About Chest Pain in Women?
As has been discussed on the Cardionerds podcast (Listen to episodes with Dr. Nanette Wenger, Dr Martha Gulati, and Dr. Leslie Cho), women generally present with acute coronary syndrome at a later age, with a higher burden of risk factors than men, and with greater symptom burden but are less likely to be treated with guideline-directed medical therapies, undergo cardiac catheterization and receive timely reperfusion. In one study of young patients with acute MI, women – 19% of cases overall – were less likely to undergo revascularization or receive guideline-directed therapy
The construct of classifying chest pain as “typical” and “atypical” likely leads to misdiagnosis or delayed diagnosis of acute myocardial infarction in women. Rather, it is important to recognize that while symptoms may not be “typical” for angina, coronary disease can manifest in many different ways.
While many women will presents with chest pain suggestive of angina, women are more likely than men to present with dyspnea, indigestion, weakness, nausea/vomiting and/or fatigue. Note, shoulder pain and arm pain are twice as predictive of an acute myocardial infarction diagnosis in women compared with men.
Furthermore, while obstructive epicardial disease remains the primary cause of acute MI in young women, it is also important to keep other causes of chest pain such as MINOCA, SCAD (see the UCLA episode), peripartum cardiomyopathy (see the Penn and MCW episodes), or coronary vasculitis on the differential. While these etiologies are rare, they are disproportionately represented in young women.
3. How do we think about categorizing vasculitis?
Vasculitis is a broad term encompassing many forms of vessel wall (including arteries, veins or capillaries) inflammation. This can be secondary to autoimmunity, infection, drug reaction, and malignancy to name a few underlying causes.
Generally vasculitis is divided by large vessel (e.g., Takayasu, Giant Cell), medium vessel (e.g., Polyarteritis Nodosa), and small vessel etiologies (e.g., Granulomatosis with Polyangitis, Eosinophilic Granulomatosis with Polyangiitis, Microscopic Polyangitis, Immune-mediated Vasculitis, amongst others). This characterization follows the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitis.
Other important categories includes variable vessel vasculitis (e.g., Behcet’s Disease, Cogan’s Syndrome) and vasculitis associated with systemic disease (e.g., Lupus vasculitis, Rheumatoid vasculitis, Sarcoid vasculitis).
4. What Does Vasculitis Look Like in the Heart?
While inflammation can occur throughout the heart – e.g., pericarditis or myocarditis – vasculitis in the heart refers specifically to inflammation of the coronary arteries. This is a relatively rare process, with <10% of vasculitis patients exhibiting cardiac involvement.
Patients with coronary vasculitis rarely present with isolated coronary involvement and typically have systemic manifestations, such as constitutional symptoms in addition to cardiac symptoms (e.g., angina, heart failure, arrhythmia). Examination may reveal asymmetric pulses or BP readings between limbs and arterial bruits, with imaging revealing multi-organ infarcts without a clear embolic origin. Amongst the vasculitides, Takayasu Arteritis (TA) is one of the more frequent etiologies of coronary arteritis.
In Takayasu Arteritis (TA), the affected arteries are typically the aorta and its major branches. In contrast to giant cell arteritis (GCA), TA is quite rare and tends to have onset <40 years age; however, for both diagnoses coronary involvement is rare. TA patients will typically have constitutional symptoms and may have diminished/absent arterial pulses often accompanied by bruits. Weakness of the arterial walls may lead to aneurysms and specifically aortic root aneurysm may result in aortic valve insufficiency. When involving the coronaries, there are three main type of TA lesions: stenosis or occlusion of the ostia/proximal segments (Type 1); diffuse or focal coronary vasculitis involving all the epicardial branches or focal areas (Type 2); coronary aneurysms (Type 3).
5. What Are the Complications of Coronary Vasculitis?
The consequences of coronary vasculitis are variable and much of the data we have comes from case reports. As in the case presented, severe coronary ischemia and its complications, including arrhythmia and cardiac arrest, are a major concern. However, cardiac arrest is rarely the first presentation of coronary vasculitis, especially if it is detected early. The manifestations of coronary vasculitis are also going to be dependent on the specific etiology of the arteritis.
Amongst the medium vessel vasculitis and specifically polyarteritis nodosa, 15-20% of patients will have cardiac involvement, with major complications including heart failure, myocardial infarction, or arrhythmia.
Amongst the small vessel vasculitis, eosinophilic granulomatosis with polyangiitis is the most common culprit for cardiac involvement, primarily secondary to eosinophilic toxicity. Cardiac involvement is a major cause of mortality and poor prognostic sign in EGPA.
The CardioNerds Cardiology Case Reports series shines light on the hidden curriculum of medical storytelling. We learn together while discussing fascinating cases in this fun, engaging, and educational format. Each episode ends with an “Expert CardioNerd Perspectives & Review” (E-CPR) for a nuanced teaching from a content expert. We truly believe that hearing about a patient is the singular theme that unifies everyone at every level, from the student to the professor emeritus.
We are teaming up with the ACC FIT Section to use the #CNCR episodes to showcase CV education across the country in the era of virtual recruitment. As part of the recruitment series, each episode features fellows from a given program discussing and teaching about an interesting case as well as sharing what makes their hearts flutter about their fellowship training. The case discussion is followed by both an E-CPR segment and a message from the program director.
References
Kostner, M. J., & Warrington, K. J. (2019, March 13). Vasculitis of the Coronary Arteries. ACC.org.
Ward, E. V., Nazari, J., & Edelman, R. R. (2012). Coronary artery vasculitis as a presentation of cardiac sarcoidosis. Circulation, 125(6), e344-e346.
Awad, H. H., McManus, D. D., Anderson Jr, F. A., Gore, J. M., & Goldberg, R. J. (2013). Young patients hospitalized with an acute coronary syndrome. Coronary Artery Disease, 24(1), 54-60.
Bugiardini, R., Cenko, E. (2020). Sex differences in myocardial infarction deaths. Lancet, 396:72–73
DeFilippis, E.M., Collins, B.L., Singh A., et. al Women who experience a myocardial infarction at a young age have worse outcomes compared with men: the Mass General Brigham YOUNG-MI registry, European Heart Journal, ehaa662
Miloslavsky, E., & Unizony, S. (2014). The heart in vasculitis. Rheumatic Disease Clinics, 40(1), 11-26.
Mehta LS, Beckie TM, DeVon HA et al; American Heart Association Cardiovascular Disease in Women and Special Populations Committee of the Council on Clinical Cardiology, Council on Epidemiology and Prevention, Council on Cardiovascular and Stroke Nursing, and Council on Quality of Care and Outcomes Research. (2016) Acute Myocardial Infarction in Women: A Scientific Statement From the American Heart Association. Circulation. Mar 1;133(9):916-47. doi: 10.1161/CIR.0000000000000351.
CardioNerds Case Reports: Recruitment Edition Series Production Team
Bibin Varghese, MD
Rick Ferraro, MD
Tommy Das, MD
Eunice Dugan, MD
Evelyn Song, MD
Colin Blumenthal, MD
Karan Desai, MD
Amit Goyal, MD
Daniel Ambinder, MD

Feb 14, 2021 • 37min
102. Nuclear and Multimodality Imaging: Myocardial Viability
Join Dr. Erika Hutt, Dr. Aldo Schenone, and Dr. Wael Jaber as they discuss nuclear and multimodality imaging for myocardial viability. Learn about the spectrum of myocardial changes in response to ischemia, the importance of viability testing for identifying patients who may benefit from revascularization, and the various imaging modalities available for evaluation. Explore techniques like echocardiography, thallium, and PET in assessing viability, and understand the role of imaging in determining treatment approaches for patients with CAD.

Feb 7, 2021 • 25min
101. Nuclear and Multimodality Imaging: Coronary Microvascular Disease
CardioNerd Amit Goyal is joined by Dr. Erika Hutt (Cleveland Clinic general cardiology fellow), Dr. Aldo Schenone (Brigham and Women’s advanced cardiovascular imaging fellow), and Dr. Wael Jaber (Cleveland Clinic cardiovascular imaging staff and co-founder of Cardiac Imaging Agora) to discuss nuclear and complimentary multimodality cardiovascular imaging for the evaluation of coronary microvascular disease. To learn more about multimodality cardiovascular imaging, check out Cardiac Imaging Agora!
Collect free CME/MOC credit just for enjoying to the episode!
CardioNerds Multimodality Cardiovascular Imaging PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll
Subscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron!
Guest Profiles
Wael Jaber, MD
Wael Jaber, MD, is a staff cardiologist in the Section of Cardiovascular Imaging, Robert and Suzanne Tomsich Department of Cardiovascular Medicine, at the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic. Dr. Jaber specializes in cardiac imaging (both nuclear cardiology and echocardiography) and valvular heart disease. Dr. Jaber attended college at the American University in Beirut, graduating with a Bachelor of Science in biology. He then went on at the American University to receive his medical degree while making the Dean’s honor list. He completed his residency in internal medicine at the St. Luke’s-Roosevelt Hospital Center at Columbia University College of Physicians and Surgeons, where he also completed fellowships in cardiovascular medicine and nuclear cardiology. Dr. Jaber is currently is the Medical Director of the Nuclear Lab and of the Cardiovascular Imaging Core Laboratory in C5Research. He is fluent in English, French and Arabic. He is the author of Nuclear Cardiology review: A Self-Assessment Tool and cofounder of Cardiac Imaging Agora.
Dr. Aldo L Schenone
Dr. Aldo L Schenone is one of the current Chief Non-Invasive Cardiovascular Imaging Fellows at the Brigham and Women’s Hospital. He completed medical school at the University of Carabobo in Valencia, Venezuela, and then completed both his Internal Medicine residency and Cardiology fellowship at the Cleveland Clinic where he also served as a Chief Internal Medicine Resident.
Dr. Erica Hutt
Dr. Erika Hutt @erikahuttce is a cardiology fellow at the Cleveland Clinic. Erika was born and raised in Costa Rica, where she received her MD degree at Universidad de Costa Rica. She then decided to pursue further medical training in the United States, with the goal of becoming a cardiologist. She completed her residency training at Cleveland Clinic and went on to fellowship at the same institution. Her passions include infiltrative heart disease, atrial fibrillation, valvular heart disease and echocardiography among many. She is looking forward to a career in advanced cardiovascular imaging.
References and Links
Kaski, J.-C., Crea, F., Gersh, B. J., & Camici, P. G. (2018). Reappraisal of Ischemic Heart Disease. Circulation. https://doi.org/10.1161/circulationaha.118.031373
Jaber, W., & Gimelli, A. (n.d.). Cardiac Imaging Agora. https://www.cardiacimagingagora.com/list/
Taqueti, V. R., & Di Carli, M. F. (2018). Coronary Microvascular Disease Pathogenic Mechanisms and Therapeutic Options: JACC State-of-the-Art Review. In Journal of the American College of Cardiology. https://doi.org/10.1016/j.jacc.2018.09.042
Wael Jaber, MD
Dr. Aldo L Schenone
Dr. Erika Hutt
Dr. Madiha Khan
Amit Goyal, MD

Feb 4, 2021 • 56min
100. Women’s Heart Health & Women in Cardiology with Dr. Nanette Wenger – Special Go Red Encore
CardioNerds (Amit Goyal & Carine Hamo) discuss the past, present, and future of Women’s Heart Health & Women in Cardiology with Dr. Nanette Wenger, Professor of Medicine in the Division of Cardiology at the Emory University School of Medicine. Dr. Wenger is a true leader in the field of women’s heart health and a strong proponent for women in cardiology and medicine. Her passion, dedication, and advocacy have inspired countless trainees to carry this torch and continue to build on her truly impactful work. Special introduction by Dr. Martha Gulati. This is a special encore in recognition of the Go Red campaign and celebration of women’s health.
Collect free CME/MOC credit for enjoying this episode!
Episode graphic by Dr. Carine Hamo
The Cardionerds CV prevention series includes in-depth deep dives on so many prevention topics including the ABCs of prevention, approach to obesity, hypertension, diabetes mellitus and anti-diabetes agents, personalized risk and genetic risk assessments, hyperlipidemia, women’s cardiovascular prevention, coronary calcium scoring and so much more!
CardioNerds Prevention PageCardioNerds Women’s Cardiovascular Health PageCardioNerds Episode PageSubscribe to our newsletter- The Heartbeat
CardioNerds AcademyCardionerds Healy Honor RollCheck out CardioNerds SWAG!Become a CardioNerds Patron!
This episode initially ran as part of the CardioNerds Prevention Series which we produced in collaboration with the American Society for Preventive Cardiology! The ASPC is an incredible resource for learning, networking, and promoting the ideals of cardiovascular prevention!
Cardionerds Cardiovascular Prevention Series
References and Links
1. Wenger NK (2005) Women in cardiology: The US experience. Heart.
2. Douglas PS, Rzeszut AK, Noel Bairey Merz C, Duvernoy CS, Lewis SJ, Walsh MN, Gillam L (2018) Career preferences and perceptions of cardiology among us internal medicine trainees factors influencing cardiology career choice. JAMA Cardiol.
3. Wenger NK, Speroff L, Packard B (1993) Cardiovascular Health and Disease in Women. N Engl J Med.
4. Burgess S, Shaw E, Zaman S (2019) Women in Cardiology. Circulation.
Meet Dr. Wenger!
Dr. Nanette Wenger is Professor of Medicine in the Division of Cardiology at the Emory University School of Medicine. Dr. Wenger received her medical degree from Harvard Medical School in 1954 as one of their first female graduates followed by training at Mount Sinai Hospital where she was the first female to be chief resident in the cardiology department. She is among the first physicians to focus on heart disease in women with an expertise in cardiac rehabilitation and geriatric medicine.
Dr. Wenger has received numerous awards including the Distinguished Achievement Award from the Scientific Councils of the American Heart Association and its Women in Cardiology Mentoring Award, the James D. Bruce Memorial Award of the American College of Physicians for distinguished contributions in preventive medicine, the Gold Heart Award, the highest award of the American Heart Association, a Lifetime Achievement Award in 2009 and the Inaugural Bernadine Healy Leadership in Women’s CV Disease Distinguished Award, American College of Cardiology. She chaired the U.S. National Heart, Lung, and Blood Institute Conference on Cardiovascular Health and Disease in Women, is a Past President of the Society of Geriatric Cardiology and is past Chair, Board of Directors of the Society for Women’s Health Research. Dr. Wenger serves on the editorial boards of numerous professional journals and is a sought-after lecturer for issues related to heart disease in women, heart disease in the elderly, cardiac rehabilitation, coronary prevention, and contemporary cardiac care. She is listed in Best Doctors in America.
Carine Hamo, MD
Amit Goyal, MD

Jan 31, 2021 • 56min
99. Nuclear and Multimodality Imaging: Coronary Ischemia
CardioNerd Amit Goyal is joined by Dr. Erika Hutt (Cleveland Clinic general cardiology fellow), Dr. Aldo Schenone (Brigham and Women’s advanced cardiovascular imaging fellow), and Dr. Wael Jaber (Cleveland Clinic cardiovascular imaging staff and co-founder of Cardiac Imaging Agora) to discuss nuclear and complimentary multimodality cardiovascular imaging for the evaluation of coronary ischemia. Show notes were created by Dr. Hussain Khalid (University of Florida general cardiology fellow and CardioNerds Academy fellow in House Thomas). To learn more about multimodality cardiovascular imaging, check out Cardiac Imaging Agora!
Collect free CME/MOC credit for enjoying this episode!
CardioNerds Multimodality Cardiovascular Imaging PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll
Subscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron!
Show Notes & Take Home Pearls
Five Take Home Pearls
1. We can broadly differentiate non-invasive testing into two different categories—functional and anatomical. Functional tests allow us to delineate the functional consequence of coronary disease rather than directly characterizing the burden of disease. Anatomical tests such as coronary CTA, on the other hand, allow us to directly visualize obstructive epicardial disease.
2. In general PET imaging provides higher quality images than SPECT imaging for a variety of reasons, including a higher “keV” of energy in PET radiotracers
3. If using a SPECT camera, we should use cameras that have attenuation correction. Without attenuation correction, the specificity of a SPECT camera drops to 50-60%.
4. In evaluating ischemic heart disease, cardiac nuclear imaging can provide a wide range of information including myocardial perfusion (rest and stress), ejection fraction assessment (rest and stress), absolute myocardial blood flow with quantitative flow reserve in all coronary territories (PET), assessment of myocardial viability (PET), and calcium score with CT attenuation correction.
5. To select the best non-invasive test, we should consider a variety of factors such as pretest probability of obstructive epicardial disease, patient-specific factors (e.g., ability to exercise) and whether a functional or an anatomical test will provide the best answer for our clinical question.
Detailed Show Notes
What are the basic non-invasive testing categories for evaluation of coronary artery disease?
We have a variety of different non-invasive testing modalities that can be broadly separated into functional tests and anatomical tests.
The basic principle underlying functional stress testing is to induce ischemia or coronary vasodilation (discussed below), followed by a functional assessment by different techniques (e.g., EKG, echocardiography, radionuclide imaging) to detect flow-limiting obstructive coronary artery disease. These tests delineate the functional consequence of the coronary disease, rather than directly characterizing the burden of disease itself.
Functional tests can also allow us to assess the nature of a patient’s symptoms. For example, by having a patient exercise on a treadmill we can evaluate whether we can reproduce a patient’s chest pain syndrome.
Anatomical tests allow us to visualize the presence of obstructive epicardial disease. For example, obtaining a Coronary Computed Tomography Angiography (CCTA) for a patient with chest pain would allow you to directly visualize possible obstructive epicardial disease.
How do we induce ischemia for functional stress testing?
To induce ischemia (and/or coronary vasodilation), we have many different stressors that can be broadly separated into exercise stressors and pharmacologic stressors.
Treadmill exercise via standardized protocols is the most common method for inducing ischemia and has the advantage of assessing functional capacity, which has prognostic information. Supine bicycle is another common exercise modality that is utilized.
There are also several pharmacologic stressors that vary in their mechanisms of action. Dobutamine is a synthetic catecholamine that stimulates myocardial beta-1 and beta-2 receptors to increase heart rate, contractility, and consequently myocardial oxygen demand with a small decrease in systemic vascular resistance.
Adenosine and adenosine derivatives (e.g. regadenoson) induce coronary vasodilation and take advantage of differences in coronary flow reserve. With obstructive coronary lesions, the vessels distal to the obstruction are already dilated at baseline and have little flow reserve. Adenosine (and its derivatives) induce vasodilation and increase flow in normal coronary beds, but much less so in areas supplied by an obstructive lesion. Consequently, we can see disparate radiotracer uptake that correlates with different coronary territories.
Once we’ve induced ischemia, we can assess it via electrocardiogram (EKG) alone or in conjunction with an imaging modality such as echocardiography, MRI, or nuclear imaging — such as Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET).
What is the difference between SPECT and PET imaging quality? What are the advantages of using PET imaging?
SPECT and PET imaging both use gamma cameras that detect gamma rays produced by the injected radionuclide tracer. SPECT utilizes a single-crystal camera to acquire multiple 2D images to be reconstructed into a 3D image, while PET imaging utilizes a multi-crystal camera which can detect more counts (e.g., quantification of radioactivity).
SPECT studies usually use Technetium-based tracers which have nuclei that emit 140 keV of energy. PET studies usually use Rubidium or Ammonia which have nuclei that emit around 510 keV of energy. Either of these studies can also use Thallium which have nuclei that emit 68 keV of energy. In general, the higher the “keV”, the better the image quality. So, using thallium may result in poorer quality images and is not recommended as a first-line agent.
Rubidium has a half-life of 76 seconds and Ammonia has a half-life of 10 minutes—so it is possible to do an exercise stress test if using Ammonia but not with using Rubidium!
Because the radiotracers used for PET imaging have higher “keV” than those used in SPECT imaging, PET image quality is generally better with a higher resolution.
If using a SPECT camera, you should use a camera that has attenuation correction. Attenuation artifact can occur when you have tissue such as breast or diaphragm that overlies the myocardium and decreases the intensity/strength of signal prior to reaching the myocardium. This can result in the false appearance of a myocardial perfusion defect in that region. Without attenuation correction, the specificity of a SPECT camera drops to 50-60%.
In addition to improved spatial resolution and higher quality images resulting from using radiotracers with higher “keV”, PET cameras also do not require physical collimation. This allows for even further increase in spatial resolution and image quality.
A collimator is a piece of lead with holes that absorb and stop most photons except for those that arrive almost perpendicular to the detector face. This allows the camera to accurately localize the radiotracer in the patient’s body over the organ of interest. Overall, PET has better sensitivity, specificity, and better accuracy to diagnose 50% and 70% lesions than SPECT!
However, maintaining PET scanners comes at increased cost compared to SPECT.
What diagnostic information can cardiac nuclear imaging provide us? What are some unique uses of nuclear imaging?
In the evaluation of coronary disease, some diagnostic information provided by SPECT and PET imaging include:
Assessment of myocardial perfusion and blood flow at both rest and stress
Ejection fraction assessment at both rest and stress
Quantitative flow reserve in all coronary territories (PET)
Assessment of myocardial viability (PET)
Prognostication
Calcium Score with CT Attenuation Correction
If using CT for attenuation correction, you should also use it for calcium score. A high coronary calcium score can change management—there is also data that shows that just showing patients the plaque on CT imaging can improve outcomes!
There are many uses of nuclear imaging, and novel uses are continuously being described. In addition to its use in noninvasive stress testing and ischemic heart disease, we can also use it to assess etiology of cardiomyopathies:
In patients with suspected cardiac sarcoidosis, fluorodeoxgylocse(FDG)-PET imaging with Rubidium can be utilized to detect sarcoid and prognosticate. Enjoy the upcoming discussion about sarcoidosis imaging as well as the CNCR from the University of Chicago!
Nuclear scintigraphy with 99m-Technetium pyrophosphate can be used to assess for cardiac amyloidosis. Stay tuned for more on this as part of the amyloidosis imaging discussion.
FDG PET and whole-body-white blood cell scan can be used to help evaluate for prosthetic valve endocarditis or LVAD-associated infections, which we will also discuss later in this imaging series!
FDG-PET can help evaluate and differentiate aortopathies in patients presenting with chest pain
Many novel uses of nuclear stress testing are being described for patients admitted to the cardiac intensive care unit (CICU).
CT imaging and MRI require significant patient cooperation. MRI additionally is sometimes limited by patient compatibility issues. A full PET study can be done in 20-25 minutes, however, independent of renal and hepatic function.
In patients admitted to the CICU with an intra-aortic balloon pump (IABP), exercise can be simulated by reducing the IABP support ratio from 1:1 to 1:3. A PET stress test can then be conducted using this “exercise” to evaluate for myocardial ischemia.
How do you select the best non-invasive test?
A variety of factors play a role in this decision. To begin, you can start with the picking whether a functional test or an anatomical test is best to answer your clinical question.
Are you trying to identify the nature of a patient’s symptoms for a possible underlying cardiac etiology? Perhaps a functional test is best.
Are you trying to rule out obstructive epicardial disease? Perhaps an anatomical test is best.
In many instances functional and anatomical tests provide complimentary information. And if the patient has had multiple prior non-invasive testing of the same modality with equivocal answers to the clinical question, it may be more helpful to switch to a different modality.
Many imaging and individual patient factors affect the selection for the best non-invasive test. For instance:
Patient factors/comorbidities such as kidney disease, liver disease, devices, metallic implants, ability to exercise, baseline abnormal ECG or TTE, and patient cooperation issues affect the selection for the best non-invasive test.
Cost-effectiveness of the study and radiation exposure should be a consideration.
If the patient has a low pretest probability of obstructive CAD, perhaps testing is not needed, or you could consider an anatomical test such as a Coronary CTA
If the patient has a low-intermediate pretest probability of obstructive CAD, one could consider obtaining CCTA anatomical testing in addition to an exercise tolerance test (ETT) with or without imaging as this has been shown to provide higher diagnostic ability and affects management. Rather than have premature closure when obstructive epicardial disease is ruled out, we can assess for nonobstructive plaque that warrants initiation of aggressive lifestyle and risk factor modifications.
If the patient has a significant cardiovascular disease history (e.g. multiple prior stents or bypass surgery) but lower suspicion of symptomatic coronary ischemia, perhaps functional testing such as stress MRI, nuclear stress test, or stress echocardiogram is preferred.
If the patient has a high pretest probability of obstructive epicardial disease, perhaps it is best to skip a non-invasive test and proceed straight to an invasive test.
Do note that patients with angina who do not have obstructive epicardial stenoses on anatomical testing may have coronary microvascular disease which is still important to diagnose given important therapeutic and prognostic implications. More on this in the next episode!
Below is a depiction of the how effective the different non-invasive modalities are to rule in or rule out significant coronary artery disease in stable CAD patients. It is based on follow-up invasive coronary angiography or FFR assessment, stratified by pretest probability. Notably, stress ECG requires a relatively lower pretest probability to rule out obstructive CAD and relatively higher pretest probability to rule in CAD. CCTA does not perform as well as functional imaging techniques in ability to rule-in and rule out FFR-significant CAD when comparing it to its ability to rule in and rule out significant CAD by invasive coronary angiography.
Guest Profiles
Wael Jaber, MD
Wael Jaber, MD, is a staff cardiologist in the Section of Cardiovascular Imaging, Robert and Suzanne Tomsich Department of Cardiovascular Medicine, at the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic. Dr. Jaber specializes in cardiac imaging (both nuclear cardiology and echocardiography) and valvular heart disease. Dr. Jaber attended college at the American University in Beirut, graduating with a Bachelor of Science in biology. He then went on at the American University to receive his medical degree while making the Dean’s honor list. He completed his residency in internal medicine at the St. Luke’s-Roosevelt Hospital Center at Columbia University College of Physicians and Surgeons, where he also completed fellowships in cardiovascular medicine and nuclear cardiology. Dr. Jaber is currently is the Medical Director of the Nuclear Lab and of the Cardiovascular Imaging Core Laboratory in C5Research. He is fluent in English, French and Arabic. He is the author of Nuclear Cardiology review: A Self-Assessment Tool and cofounder of Cardiac Imaging Agora.
Dr. Aldo L Schenone
Dr. Aldo L Schenone is one of the current Chief Non-Invasive Cardiovascular Imaging Fellows at the Brigham and Women’s Hospital. He completed medical school at the University of Carabobo in Valencia, Venezuela, and then completed both his Internal Medicine residency and Cardiology fellowship at the Cleveland Clinic where he also served as a Chief Internal Medicine Resident.
Dr. Erica Hutt
Dr. Erika Hutt @erikahuttce is a cardiology fellow at the Cleveland Clinic. Erika was born and raised in Costa Rica, where she received her MD degree at Universidad de Costa Rica. She then decided to pursue further medical training in the United States, with the goal of becoming a cardiologist. She completed her residency training at Cleveland Clinic and went on to fellowship at the same institution. Her passions include infiltrative heart disease, atrial fibrillation, valvular heart disease and echocardiography among many. She is looking forward to a career in advanced cardiovascular imaging.
References and Links
Pitman AG, Kalff V, Van Every B, Risa B, Barnden LR, Kelly MJ. Contributions of subdiaphragmatic activity, attenuation, and diaphragmatic motion to inferior wall artifact in attenuation-corrected Tc-99m myocardial perfusion SPECT. J Nucl Cardiol. 2005;12:401–9.
Heller GV, Bateman TM, Johnson LL, Cullom SJ, Case JA, Galt JR, et al. Clinical value of attenuation correction in stress-only Tc-99m sestamibi SPECT imaging. J Nucl Cardiol. 2004;11:273–81.
Maddahi J, Packard RR. Cardiac PET perfusion tracers: current status and future directions. Semin Nucl Med. 2014;44(5):333-343. doi:10.1053/j.semnuclmed.2014.06.011
van Dalen JA, Visser EP, Vogel WV, Corstens FH, Oyen WJ. Impact of Ge-68/Ga-68-based versus CT-based attenuation correction on PET. Med Phys. 2007 Mar;34(3):889-97. doi: 10.1118/1.2437283.
Parker MW, Iskandar A, Limone B, Perugini A, Kim H, Jones C, Calamari B, Coleman CI, Heller GV. Diagnostic accuracy of cardiac positron emission tomography versus single photon emission computed tomography for coronary artery disease: a bivariate meta-analysis. Circ Cardiovasc Imaging. 2012 Nov;5(6):700-7. doi: 10.1161/CIRCIMAGING.112.978270. Epub 2012 Oct 10.
Mettler FA, Guiberteau MJ. Essentials of nuclear medicine imaging. 6th ed. Philadelphia, PA: Elsevier/Saunders; 2012.
SCOT-HEART Investigators, Newby DE, Adamson PD, Berry C, Boon NA, Dweck MR, Flather M, Forbes J, Hunter A, Lewis S, MacLean S, Mills NL, Norrie J, Roditi G, Shah ASV, Timmis AD, van Beek EJR, Williams MC. Coronary CT Angiography and 5-Year Risk of Myocardial Infarction. N Engl J Med. 2018 Sep 6;379(10):924-933. doi: 10.1056/NEJMoa1805971. Epub 2018 Aug 25.
Juhani Knuuti, Haitham Ballo, Luis Eduardo Juarez-Orozco, Antti Saraste, Philippe Kolh, Anne Wilhelmina Saskia Rutjes, Peter Jüni, Stephan Windecker, Jeroen J Bax, William Wijns, The performance of non-invasive tests to rule-in and rule-out significant coronary artery stenosis in patients with stable angina: a meta-analysis focused on post-test disease probability, European Heart Journal, Volume 39, Issue 35, 14 September 2018, Pages 3322–3330, https://doi.org/10.1093/eurheartj/ehy267
Jaber W, Gimelli A. Cardiac Imaging Agora. https://www.cardiacimagingagora.com/list
Wael Jaber, MD
Dr. Aldo L Schenone
Dr. Erika Hutt
Dr. Hussain Khalid
Amit Goyal, MD

9 snips
Jan 25, 2021 • 1h 9min
98. Personalized Risk Assessment for Cardiovascular Prevention with Dr. Amit Khera
CardioNerds (Carine Hamo, Amit Goyal and Daniel Ambinder) discuss personalized risk assessment for cardiovascular prevention with Dr. Amit Khera, the immediate past president for the American Society for Preventive Cardiology and Director of the Preventive Cardiology and Professor of Medicine at the University of Texas, Southwestern Medical School in Dallas, Texas. They dive into an illuminating discussion about traditional and next generation personalization of risk assessment which covers the need for personalization, traditional risk stratification, applying risk enhancing factors for decision making, biomarkers, familial hypercholesterolemia, and the use of -Omics. This episode is the 13th and final part of our in-depth prevention series produced in collaboration with the American Society for Preventive Cardiology!
Stay tuned for a bonus segment at the end of the episodeas we talk to Dr. Ankur Kalra, interventionist at the Cleveland Clinic, Podcast host of Parallax by Ankur Kalra, and founder of the non-profit startup, makeadent.org for a discussion about the CHAI (Cardiovascular Health in Asian Indians) Collaborative, an initiative that aims to identify genetic markers of heightened atherosclerosis in South Asians.
Episode graphic by Dr. Carine Hamo
CardioNerds Cardiovascular Prevention PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll
Subscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron!
Show notes
Coming soon!
Cardionerds Cardiovascular Prevention Series
The Cardionerds CV prevention series includes in-depth deep dives on so many prevention topics including the ABCs of prevention, approach to obesity, hypertension, diabetes mellitus and anti-diabetes agents, personalized risk and genetic risk assessments, hyperlipidemia, women’s cardiovascular prevention, coronary calcium scoring and so much more!
We are truly honored to be producing the Cardionerds CVD Prevention Series in collaboration with the American Society for Preventive Cardiology! The ASPC is an incredible resource for learning, networking, and promoting the ideals of cardiovascular prevention! This series is kicked off by a message from Dr. Amit Khera, President of the American Society for Preventive Cardiology and President of the SouthWest Affiliate of the American Heart Association.
Guest Profiles
Amit Khera, MD, MSc, FACC, FAHA, FASPC
Dr. Amit Khera is Professor of Medicine at the University of Texas, Southwestern Medical School in Dallas, Texas where he serves as Director of the Preventive Cardiology, and holder of the Dallas Heart Ball Chair in Hypertension and Heart Disease. He is also currently President of the American Society for Preventive Cardiology and President of the SouthWest Affiliate of the American Heart Association. His clinical and research interests include the primary and secondary prevention of coronary artery disease, focusing on risk assessment and risk factor modification in those with premature and familial disease.
Dr. Khera received his undergraduate degree in American History from the University of Pennsylvania, with magna cum laude honors. He obtained his medical degree from Baylor College of Medicine where he served as class president and was inducted into the Alpha Omega Alpha honor medical society. He completed an Internal Medicine Residency at Brigham and Women’s Hospital, Harvard Medical School, followed by a Cardiology Fellowship at the University of Texas, Southwestern Medical Center. He also completed his Masters degree in Epidemiology at the Harvard School of Public Health.
He has published over 150 publications in the field of preventive cardiology and has served on numerous local and national committee and leadership roles for the American Heart Association, American College of Cardiology, and American Society for Preventive Cardiology. He is currently Digital Strategies Editor and an Associate Editor for the journal Circulation. Dr. Khera has been named Best Doctor in Dallas and Texas SuperDoctor every year since 2014 and was previously the Program Director for the Cardiology Fellowship at UT Southwestern from 2011-2019.
References and Links
Coming soon!
Amit Khera, M.D.
Carine Hamo, MD
Amit Goyal, MD
Daniel Ambinder, MD

Jan 18, 2021 • 32min
97. Hypertension part 2 with Dr. Luke Laffin
CardioNerds (Amit Goyal and Daniel Ambinder) are joined by Cleveland Clinic cardiology fellow Dr. Gregory Ogunnowo to discuss hypertension with Dr. Luke Laffin, cardiology faculty in the division of Preventive Cardiology and Rehabilitation and Medical Director of Cardiac Rehabilitation at the Cleveland Clinic. Part 2 of this discussion covers the evaluation for secondary causes of HTN, approach to resistant HTN, interventional anti-hypertensive procedures, and a note on cardiac rehabilitation. Part 1 covered the definition of hypertension, correct measurement of blood pressure, nonpharmacologic HTN management, initial choice of BP agents, and hypertensive disorders of pregnancy.
Episode graphic by Dr. Carine Hamo
CardioNerds Cardiovascular Prevention PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll
Subscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron!
Show notes
Coming soon!
Cardionerds Cardiovascular Prevention Series
The Cardionerds CV prevention series includes in-depth deep dives on so many prevention topics including the ABCs of prevention, approach to obesity, hypertension, diabetes mellitus and anti-diabetes agents, personalized risk and genetic risk assessments, hyperlipidemia, women’s cardiovascular prevention, coronary calcium scoring and so much more!
We are truly honored to be producing the Cardionerds CVD Prevention Series in collaboration with the American Society for Preventive Cardiology! The ASPC is an incredible resource for learning, networking, and promoting the ideals of cardiovascular prevention! This series is kicked off by a message from Dr. Amit Khera, President of the American Society for Preventive Cardiology and President of the SouthWest Affiliate of the American Heart Association.
Guest Profiles
Dr. Luke Laffin, serves as cardiology faculty in the division of Preventive Cardiology and Medical Director of Cardiac Rehabilitation at the Cleveland Clinic. Dr. Laffin attended medical school at Vanderbilt University School of Medicine. He trained in internal medicine and cardiology at the University of Chicago where he completed a dedicated fellowship in hypertensive diseases. He is a clinical specialist in hypertension designated by the American Society of Hypertension – which has now merged with the AHA.
Dr. Gregory Ogunnowo is a cardiology fellow at the Cleveland Clinic. He completed medical school at the University of South Carolina School of Medicine in Columbia, South Carolina. He went on to complete internal medicine residency at Washington University School of Medicine in St. Louis where he stayed on as faculty in the Department of Hospital Medicine for a year prior to pursing fellowship. His interests include outcomes research in interventional cardiology and medical education In his spare time, Greg enjoys traveling, exercising, and experiencing new cultures through their food. When he’s not in the hospital, you can find Greg planning a trip with close friends and family.
References and Links
Coming soon!
Luke Laffin MD
Greg Ogunnowo, MD
Amit Goyal, MD
Daniel Ambinder, MD


