Category: Image of the Month

Author: S Chadalavada

Case Summary

An interesting case of a 27-year-old male with a rare homozygous splice mutation which led to ESRF and kidney transplant at age of 21. The congenital condition also led to complex LV outflow obstruction with a fibromuscular shelf and fibrosis extending to native aortic valve and MV apparatus. This required myectomy aged 10 and mechanical AVR and MVR and repeat sub-aortic myomectomy aged 20. While clinically stable, and asymptomatic on warfarin and tacrolimus, was noted to have high gradients across mitral valve on follow up echocardiography. Therefore, a TOE was requested.

Impression from TOE:

• Posterior leaflet appears fixed with strands of fibrinous material ?thrombus.
• AMVL is seen to move normally.
• Significantly raised gradients 17mmHg across MV (context of tachycardia, HR: 108).
• Mild – moderate transvalvular MR.

Cardiac CT requested to understand valves better.

Retrospective CTCA performed with 10mg IV metoprolol given as preparation.

CTCA first highlights significant calcification around the mitral valve annulus not apparent on the TOE (Multi-planar reconstructions shown in Figures 1 – 3)

Figure 1

Figure 2

Figure 3

Further postprocessing using tools on cardiac function and reconstruction modules built-in the vendor software (Syngo.via) were used to produce anatomical depictions and cines of both valves. Valve cines showed valves seen to open and close normally. No pannus/ thrombus.

CT scan informed MDT decision, which were reassured that the valve is opening and closing normally. Increased warfarin range to 2.5 – 3.5 to avoid possibility of thrombus. Under regular follow up with serial echocardiograms.

Not the end of the story……

Figure 4

Lung imaging on cardiac CT showed left-sided asymmetrical pulmonary oedema (see red arrow).

This is a very rare presentation thought to be due to congestion in the common left pulmonary vein (blue arrow) secondary to turbulent blood flow around the posterior mitral valve leaflet.

Discussion:

Use of CT to assess valves (especially prosthetic) is supported as an adjunct imaging modality when echo is not able to assess fully (acoustic shadowing can impact image quality in echo). Radiation is a concern but can be limited by controlling HR (when appropriate) and dose modulation. Photon counting scanners coming online can potentially improve further.

Quiz:

1. Which of the following is a recognised advantage of cardiac CT cine reconstructions in evaluating suspected prosthetic valve obstruction?
   A. They can quantify mitral valve mean gradient more accurately than Doppler
   B. They demonstrate dynamic leaflet motion throughout the cardiac cycle despite prosthesis-related ultrasound artefact
   C. They eliminate the need for TOE in all patients with suspected valve thrombosis
   D. They provide better assessment of valvular regurgitation direction than colour Doppler

2. When evaluating suspected prosthetic valve obstruction on cardiac CT, which imaging characteristic helps distinguish pannus from thrombus?

A. Thrombus typically has higher CT attenuation (Hounsfield units) than pannus
B. Pannus usually appears as a low-attenuation mass without leaflet restriction
C. Pannus demonstrates higher attenuation and is more fibrotic, whereas thrombus is lower-attenuation and may be mobile
D. Both pannus and thrombus have identical attenuation and must be diagnosed surgically

Answers and explanation:

1 – B –

Cine CT allows visualisation of valve leaflet motion frame-by-frame, even when echocardiography is limited by metallic artefact or acoustic shadowing. This makes CT particularly helpful in differentiating restricted mechanical leaflet motion from normal function, and in identifying pannus vs. thrombus.

2 – C –

On cardiac CT:

• Pannus is dense, fibrotic, and fixed, showing higher attenuation (≈ >145 HU).
• Thrombus is typically lower attenuation (≈ <90 HU) and may be more soft and mobile.
  CT is therefore especially helpful when echo cannot clearly differentiate the two due to acoustic shadowing.

References:

1. 2021 ESC/ EACTS Guidelines for the management of valvular heart disease. Alec Vahanian, Friedhelm Beyersdorf, Fabien Praz, Milan Milojevic, Stephan Baldus, Johann Bauersachs, Davide Capodanno, Lenard Conradi, Michele De Bonis, Ruggero De Paulis, Victoria Delgado, Nick Freemantle, Martine Gilard, Kristina H Haugaa, Anders Jeppsson, Peter Jüni, Luc Pierard, Bernard D Prendergast, J Rafael Sádaba, Christophe Tribouilloy, Wojtek Wojakowski, ESC/EACTS Scientific Document Group , ESC National Cardiac Societies , 2021 ESC/EACTS Guidelines for the management of valvular heart disease: Developed by the Task Force for the management of valvular heart disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS), European Heart Journal, Volume 43, Issue 7, 14 February 2022, Pages 561–632, https://doi.org/10.1093/eurheartj/ehab395
2. 2024 ACC/ AHA Guidelines for valve disease. Jneid H, Chikwe J, Arnold SV, Bonow RO, Bradley SM, Chen EP, Diekemper RL, Fugar S, Johnston DR, Kumbhani DJ, Mehran R, Misra A, Patel MR, Sweis RN, Szerlip M. 2024 ACC/AHA clinical performance and quality measures for adults with valvular and structural heart disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Performance Measures. Circulation: Cardiovascular Quality and Outcomes. 2024 Apr;17(4):e000129. doi:10.1161/HCQ.0000000000000129
3. Schnyder PA, Sarraj AM, Duvoisin BE, et al. Pulmonary edema associated with mitral regurgitation: prevalence of predominant involvement of the right upper lobe. https://doi.org/102214/ajr16118517316. American Public Health Association; 2013;161(1):33–36. doi: 10.2214/AJR.161.1.8517316.
4. Woolley K, Stark P. Pulmonary Parenchymal Manifestations of Mitral Valve Disease1. https://doi.org/101148/radiographics194.g99jl10965. Radiological Society of North America ; 1999;19(4):965–972. doi: 10.1148/RADIOGRAPHICS.19.4.G99JL10965.
5. Rice J, Roth SL, Rossoff LJ. An unusual case of left upper lobe pulmonary edema. Chest. American College of Chest Physicians; 1998;114(1):328–330. doi: 10.1378/chest.114.1.328.

Author:

Dilan Sanli

University Hospital Southampton NHS Foundation Trust

Case Summary

A 31-year-old woman with a history of two previous uncomplicated pregnancies was scheduled for elective ovarian cyst removal last year. On the day of surgery, a cardiac murmur was incidentally detected, prompting further cardiac evaluation.

She denied any significant cardiac symptoms, including chest pain or exertional chest tightness. She described herself as not particularly physically active but otherwise in good general health. Her BMI was elevated at 34 kg/m², with no traditional cardiovascular risk factors. She reported occasional non-specific palpitations over the preceding 3–6 months, each episode lasting up to 48 hours, but denied presyncope, syncope, increasing fatigue, or lethargy. She was a lifelong non-smoker and abstained from alcohol. There was no history of hypertension, diabetes, renal, or hepatic disease.

On examination, cardiovascular findings were unremarkable — normal heart sounds with no audible murmur.

Investigations

Echocardiography (multiple transthoracic studies and one transoesophageal) revealed:

· Flow directed towards the main pulmonary artery

· Systolic and diastolic flow along the interventricular septum

· Markedly dilated right coronary artery (RCA)

· Left ventricle (LV) visually mildly dilated with mild systolic dysfunction for age

The findings were suspicious for either a coronary artery fistula or, more likely, anomalous left coronary artery arising from the pulmonary artery (ALCAPA), with extensive collateralization between the right and left coronaries.

A CT coronary angiogram confirmed the diagnosis:

· The left mainstem originated from the main pulmonary artery (MPA)

· The left coronary artery (LCA) was markedly dilated without plaque or stenosis

· The RCA was markedly dilated and tortuous, supplying multiple collaterals to the LCA

A cardiac MRI with stress perfusion showed:

· Overall normal LV size and function

· Minor focal hypokinesis and relative myocardial thinning at basal to mid anterior and anteroseptal segments

· No LV dilatation or hypertrophy

· No late gadolinium enhancement, indicating absence of prior infarction

Figure 1: Demonstrates LAD, originates from the main Pulmonary Artery leading to dilated and tortuous left anterior descending (LAD) artery.

Figure 2: 3D demonstration of the main pulmonary origin of the LAD.

Figure 3: Demonstrates enlarged tortuous intercoronary collateral arteries along epicardial surface of heart.

Figure 4: Demonstrates a cross-sectional view of the coronary anatomy of the patient.

Figure 5: Take a note of the change of the contrast opacification from the right ventricular outflow tract into the main pulmonary artery due to reversal of flow.

Figure 6: Following the corrective surgery, the left coronary arises from the ascending aorta and is tunnelled through the main pulmonary artery trunk.

Discussion:

Anomalous Left Coronary Artery from the Pulmonary Artery (ALCAPA) is a rare congenital cardiac anomaly, accounting for only 0.25–0.5% of all congenital heart defects.

In utero and for several weeks after birth, the coronary circulation is adequately perfused due to the high neonatal pulmonary vascular resistance (PVR) and the presence of the patent ductus arteriosus (PDA). Though the myocardium is perfused with desaturated blood from the pulmonary artery, this is adequate to maintain myocardial oxygen delivery and adequate ventricular function. With ductal closure and a progressive decline in PVR in the first two to three months of life, coronary flow reverses due to the lower pressure in the pulmonary circulation, producing a left-to-right shunt and a coronary steal phenomenon, resulting in decline in myocardial perfusion. Without sufficient collateralization from the RCA, this leads to myocardial ischemia, LV dysfunction, and infarction within weeks to months of life.

In infancy, ALCAPA typically presents as Bland-White-Garland syndrome, characterized by crying during feeds (angina equivalent), diaphoresis, tachypnoea, and grunting. Infants may feed briefly (“snackers”) and show signs of fatigue, pallor, or failure to thrive. In adults, presentation is variable; ranging from asymptomatic cases discovered incidentally, to exertional dyspnoea, arrhythmia, or sudden cardiac death.

ALCAPA is characterized by a chronically ischemic but potentially viable myocardium. If uncorrected, mortality is extremely high; however, survival into adulthood may occur in rare cases with well-developed collaterals. Chronic subendocardial ischemia and fibrosis increase the risk of sudden cardiac death due to ventricular arrhythmias.

Management

Diagnosis of ALCAPA constitutes an absolute indication for surgical correction, with the goal of establishing a two-coronary-artery system. The preferred approach is direct reimplantation of the LCA into the aorta. If this is not technically feasible, alternative options include creation of an intrapulmonary tunnel (Takeuchi procedure) or other revascularization techniques.

Teaching Points

· ALCAPA should be considered in any infant with dilated cardiomyopathy or myocardial ischemia without obstructive coronary disease.

· In adults, prominent coronary collaterals and an enlarged RCA should raise suspicion.

· CT and MRI provide detailed anatomic and functional assessment, complementing echocardiography.

· Early diagnosis and surgical revascularization are lifesaving and prevent irreversible myocardial damage.

QUIZ:

1) A 4-month-old infant with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), severe mitral regurgitation, and a dilated left ventricle with severely diminished ventricular function is admitted to the cardiac ICU in severe congestive heart failure. The mitral valve papillary muscles are noted to be echo-bright. In patients with ALCAPA, which of the following co-existing lesions is MOST LIKELY to be associated with a less severe degree of myocardial ischemia?

A. Mitral regurgitation

B. Atrial septal defect

C. Ventricular septal defect

D. Pulmonary stenosis

2) Which of the following is the most associated valvular abnormality in ALCAPA?

A. Mitral Regurgitation

B. Tricuspid Regurgitation

C. Aortic Regurgitation

D. Pulmonary stenosis

Answers:

1. C – Explanation: Associated anomalies, such as a PDA or ventricular septal defect (VSD), lead to a gradual increase in left to right intracardiac shunt as PVR falls and thus, increased PVR related to increased blood flow. This may create a “protective” effect on the ventricular muscle by maintaining higher coronary perfusion pressure and myocardial oxygen delivery.
2. A – Explanation: Myocardial ischaemia leads to LV dilatation which leads to mitral regurgitation.

References:

1. https://radiopaedia.org/articles/anomalous-left-coronary-artery-from-the-pulmonary-artery

2. Yu J, Ren Q, Liu X, et al. Anomalous left coronary artery from the pulmonary artery: Outcomes and management of mitral valve. Front Cardiovasc Med. 2022;9:953420. doi: 10.3389/fcvm.2022.953420

3. Cottrill CM, Davis D, McMillen M, O’Conner WN, Noonan JA, Todd EP. Anomalous Left Coronary Artery from the Pulmonary Artery: Significance of Associated Intracardiac Defects. J Am Coll Cardiol. 1985; 6: 237-242.

4. https://heart.bmj.com/content/83/1/e2

Author

Dr Phyo Khaing, British Heart Foundation Centre of Research Excellence, University of Edinburgh, United Kingdom

Case history:

A 61-years old lady underwent a research computed tomography coronary angiogram (CTCA) as per the allocated trial randomisation. She was generally fit and well, and has a history of mild hypercholesterolaemia. Her research CTCA revealed an incidental finding of a rare coronary anomaly with no evidence of coronary atheroma. She had an anomalous origin of the right coronary artery arising from the left sinus of Valsalva with an intra-arterial course. Given she was entirely asymptomatic at the age of 61, her risk of sudden cardiac death was deemed low and she was managed conservatively.

Discussion:

Coronary artery anomalies are rare congenital variations, often detected incidentally during CT coronary angiography and are present in less than 2% of the population¹. The incidence of anomalous origin of the right coronary artery is more common than anomalous origin of the left coronary artery². Although patients are usually asymptomatic, coronary anomalies can present with exertional syncope, angina, palpitations and sudden cardiac death depending on the level of patient’s activity and course of the vessel. Certain anatomical features are typically considered higher risk, and these include an acute angulation at the coronary origin, a slit-like ostium, an initial intramural course within the aortic wall, and an interarterial course between the aorta and pulmonary trunk³.

Previous research based on a registry of 6.3 million military recruits showed that among 126 non-traumatic deaths, 21 were attributed to coronary artery anomalies⁴. Amongst all these coronary artery anomaly deaths, the abnormality was the left coronary artery arising from the right coronary sinus with an interarterial course.

Several mechanisms have been proposed to explain the myocardial ischaemia and sudden cardiac death in anomalous interarterial courses. These include dynamic compression of the coronary artery between the great vessels during intense exertion, transient occlusion at the ostium due to an acute angulation, and hypoplasia of the anomalous coronary artery at its ostium⁵.

In contrast to left sided coronary anomalies, an anomalous right coronary artery arising from the left sinus of Valsalva is generally considered to have a more favourable prognosis. In this case, the risk of sudden cardiac death is lower when identified later in life without any troublesome symptoms.

Questions:

What does ALCAPA stand for?

1. Anomalous Left Coronary Artery from the Pulmonary Artery
2. Anomalous Left Circumflex Artery from the Pulmonary Artery
3. Anomalous Left Coronary Artery from the Posterior Aorta
4. Anomalous Left Circumflex Artery from the Posterior Aorta

Which surgical approach is commonly used to treat a high risk coronary anomaly if necessary?

1. Aortic root replacement
2. Septal myectomy
3. Coronary unroofing
4. Shunting

Which of the following courses is generally considered benign?

1. Interarterial course
2. Intramural course
3. Retroaortic course
4. Acute angle takeoff

Answers: a, c, c

References:

1. Cheezum MK, Ghoshhajra B, Bittencourt MS, Hulten EA, Bhatt A, Mousavi N, Shah NR, Valente AM, Rybicki FJ, Steigner M, Hainer J, MacGillivray T, Hoffmann U, Abbara S, Di Carli MF, DeFaria Yeh D, Landzberg M, Liberthson R, Blankstein R. Anomalous origin of the coronary artery arising from the opposite sinus: prevalence and outcomes in patients undergoing coronary CTA. Eur Heart J Cardiovasc Imaging. 2017 Feb;18(2):224-235. doi: 10.1093/ehjci/jev323. Epub 2016 Feb 3. PMID: 26848152; PMCID: PMC6279103.
2. Heo W, Min HK, Kang DK, Jun HJ, Hwang YH, Lee HC. Three different situations and approaches in the management for anomalous origin of the right coronary artery from the left coronary sinus: case report. J Cardiothorac Surg. 2014 Jan 23;9:21. doi: 10.1186/1749-8090-9-21. PMID: 24450442; PMCID: PMC3902410.
3. Bhatia, R.T., Forster, J., Ackrill, M.et al.Coronary artery anomalies and the role of echocardiography in pre-participation screening of athletes: a practical guide. Echo Res Pract 11, 5 (2024). https://doi.org/10.1186/s44156-024-00041-4
4. Eckart RE, Scoville SL, Campbell CL, Shry EA, Stajduhar KC, Potter RN, Pearse LA, Virmani R. Sudden death in young adults: a 25-year review of autopsies in military recruits. Ann Intern Med. 2004 Dec 7;141(11):829-34. doi: 10.7326/0003-4819-141-11-200412070-00005. PMID: 15583223.
5. Fuglsang S, Heiberg J, Byg J, Hjortdal VE. Anomalous origin of the right coronary artery with an interarterial course and intramural part. Int J Surg Case Rep. 2015;14:92-4. doi: 10.1016/j.ijscr.2015.07.018. Epub 2015 Jul 28. PMID: 26255002; PMCID: PMC5963140.

Arterial phase axial CT image of the lower chest showing a left ventricular apical thrombus.

Transthoracic echocardiogram – apical 4-chamber view showing an apical thrombus in the left ventricle.

Arterial phase CT imaging of the abdomen showing thrombus in the proximal superior mesenteric artery on both axial and sagittal images.

Questions

Which one of the following statements is false?

1. Severely impaired LV ejection fraction is a strong predictor of LVT formation after MI.
2. Patients with dilated cardiomyopathy have a higher prevalence of thrombus than patients with ischaemic cardiomyopathy.
3. Elevated D-dimer levels and reduced LV ejection fraction have been independently associated with an increased risk LV thrombus.
4. Hypertrophic cardiomyopathy does not increase the risk of LV thrombus due to the increased myocardial LV wall thickness.
5. LV thrombus is mostly diagnosed incidentally on transthoracic echocardiography.

Which statement is most accurate?

1. Pedunculated LV thrombi are at greater risk of embolic phenomenon compared with mural thrombus.
2. Transoesophageal echocardiography is particularly useful in detecting LV thrombus.
3. Contrast enhanced transthoracic echocardiography has no role in detection of LV thrombi.
4. Contrast enhanced cardiac CT should never be used in detection of left sided cardiac thrombus because of high radiation dose.
5. Tissue characterisation of left sided cardiac thrombi is excellent with contrast enhanced cardiac CT.

Regarding the role of CMR (cardiac magnetic resonance) in detecting LV thrombus, which one the following statements is false?

1. CMR is considered the best imaging technique for detection of LV thrombus.
2. CMR is great for tissue characterisation.
3. CMR has high spatial and temporal resolution as well as high soft tissue contrast.
4. CMR is particularly helpful in acutely unwell patients who cannot undergo transthoracic echocardiography.
5. CMR can also assess cardiac function, valvular anatomy, and perfusion.

(Answers:d,a,d)

Reference:

^1. Catalani, Filippo, et al. “Left Ventricular Thrombosis in Ischemic and Non-Ischemic Cardiomyopathies: Focus on Evidence-Based Treatment.” Journal of Clinical Medicine5 (2025): 1615.

Questions

1. The ‘pulmonary vein sign’ is typically seen in the lower pulmonary veins during pulmonary arterial phase imaging [TRUE/FALSE]
   1. TRUE
   2. FALSE
2. Which of the following is NOT a main cause of hypodense pulmonary vein filling defects on CT? [Select one option]

1. 1. Acute PE
   2. Proximal chronic thomboembolic pulmonary hypertension (CTEPH)
   3. PV stenosis
   4. Pulmonary arterial hypertension
   5. Acute on chronic pulmonary embolism

3. Which are radiological features of acute pulmonary embolism on CT?
   1. Filling defects in branches of the pulmonary arterial system
   2. RV dilatation
   3. Pulmonary vein sign
   4. Pulmonary infarction
   5. All of the above

(Answers:a,d,e)

Reference:

CT coronary angiogram demonstrated circumferential dilatation of the mid-to-apical left ventricular cavity.

Cardiac MRI demonstrated mildly impaired resting systolic function and circumferential hypokinesis of the mid-to-distal left ventricular myocardium. Cine images demonstrated good contraction within the basal myocardial segments. The LV was not visually dilated.

T1 mapping sequences demonstrated normal basal segment mapping times and elevated mid-distal segment mapping times. T2 images showed mid-to distal myocardial oedema and elevated T2 mapping times.

No late Gadolinium enhancement appreciated.

Questions

  What is the Echocardiographic finding that is most characteristic of Takotsubo cardiomyopathy?

1. Concentric LV Hypertrophy
2. Regional Wall motion abnormality in a single coronary territory.
3. Global hypokinesia.
4. Apical ballooning with preserved basal contraction.
5. Right ventricular dilatation.

Which is NOT a recognised complication of Takotsubo cardiomyopathy?

1. Infarct
2. Congestive Heart failure
3. LV Rupture
4. Stroke
5. Pericarditis

What is the most common demographic affected by Takotsubo cardiomyopathy?

1. Young male athletes
2. Middle aged men with diabetes
3. Post menopausal women after emotional stress
4. Children under the age of 4
5. Pregnant women in first trimester

(Answers:d,e,c)

Reference:

¹ Dawson DK. Acute stress-induced (takotsubo) cardiomyopathy. Heart 2018;104:96-102. https://doi.org/10.1136/heartjnl-2017-311579

² Weerakkody Y, Campos A, Sharma R, et al. Takotsubo cardiomyopathy. Reference article, Radiopaedia.org (Accessed on 18 May 2025) https://doi.org/10.53347/rID-25099

³ Carroll D, Campos A, Rasuli B, Takotsubo cardiomyopathy (diagnostic criteria). Reference article, Radiopaedia.org https://doi.org/10.53347/rID-94359

Questions

1. Which of the following are imaging features of pericardial agenesis ?

1. Excessive levorotation
2. Interposition of lung tissue at aortopulmonary window
3. Discontinuous segments of the pericardium in anterior aspect
4. Midline position of the trachea
5. All of the above

2. Which statement is false ?

1. Normal pericardium is 1-2mm thick
2. Pericardium is easily identified along the posterior wall of left ventricle
3. Pericardial agenesis can be misdiagnosed due to non-specific symptoms
4. ECG changes include right axis deviation with incomplete RBBB
5. None of the above

3. Which of the statement is true regarding congenital absence of the pericardium?

1. Larger defects are typically symptomatic.
2. Right sided pericardial defects are common than left sided defects.
3. Risk of herniation of the left atrial appendage in smaller defects.
4. Majority of patients require surgical intervention.
5. Cuvier duct regression is not related to pericardial agenesis.

(Answers:e,b,c)

Reference:

1.Nasser WK. Congenital diseases of the pericardium. Cardiovasc Clin. 1976;7(3):271-86. PMID: 826317.

2.Klein AL, Abbara S, Agler DA, Appleton CP, Asher CR, Hoit B, Hung J, Garcia MJ, Kronzon I, Oh JK, Rodriguez ER, Schaff HV, Schoenhagen P, Tan CD, White RD. American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease: endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2013 Sep;26(9):965-1012.e15. doi: 10.1016/j.echo.2013.06.023. PMID: 23998693.

3.BremerichJ,ReddyGP,HigginsCB.Magneticresonanceimageofcardiacstructure. In: Pohost GM, O’Rourke RA, Berman D, Shah PM, eds. Imaging in Cardiovascular Disease. Philadelphia: Lippincott Williams & Wilkins; 2000. p409, 756.

4.,Bernardinello V, Cipriani A, Perazzolo Marra M, Motta R, Barchitta A. Congenital pericardial agenesis in asymptomatic individuals: tips for the diagnosis. Circ Cardiovasc Imaging 2020;13:e010169.

5.Shiikawa M, Nakahashi K, Endo M, Shiono S. [Congenital Defect of the Pericardium Incidentally Found during Surgery for Lung Cancer:Report of a Case]. Kyobu Geka. 2021 Apr;74(4):308-312. Japanese. PMID: 33831892.

6.Robin E, Ganguly S, Fowler MS. Strangulation of the left atrial appendage
through a congenital partial pericardial defect. Chest 1975;67:354–55

7.Yared K, Baggish AL, Picard MH, Hoffmann U, Hung J. Multimodality imaging of pericardial diseases. JACC Cardiovasc Imaging. 2010 Jun;3(6):650-60. doi: 10.1016/j.jcmg.2010.04.009. PMID: 20541720.

8.Abbas AE, Appleton CP, Liu PT, Sweeney JP. Congenital absence of the pericardium: case presentation and review of literature. Int J Cardiol. 2005 Jan;98(1):21-5. doi: 10.1016/j.ijcard.2003.10.021. PMID: 15676161.

9.Shah AB, Kronzon I. Congenital defects of the pericardium: a review. Eur Heart J Cardiovasc Imaging. 2015 Aug;16(8):821-7. doi: 10.1093/ehjci/jev119. Epub 2015 May 23. PMID: 26003149.

10.Iijima Y, Ishikawa M, Iwai S, Yamagata A, Motono N, Yamagishi S, Koizumi K, Uramoto H. Congenital partial pericardial defect discovered incidentally during surgery for lung cancer: a case report and literature review. BMC Surg. 2021 Dec 31;21(1):447. doi: 10.1186/s12893-021-01453-3. PMID: 34972509; PMCID: PMC8720205.

11.TanakaH,OishiY,MizuguchiY,MiyoshiH,IshimotoT,NagaseNetal.Contribution of the pericardium to left ventricular torsion and regional myocardial function in patients with total absence of the left pericardium. J Am Soc Echocardiogr 2008;21: 268 – 74.

12.Gatzoulis MA, Munk MD, Merchant N, Van Arsdell GS, McCrindle BW, Webb GD. Isolated congenital absence of the pericardium: clinical presentation, diagnosis, and management. Ann Thorac Surg. 2000 Apr;69(4):1209-15. doi: 10.1016/s0003-4975(99)01552-0. PMID: 10800821.

13.Van Son JA, Danielson DG, Schaff HV, Mullany CJ, Julsud PR, Breen JF. Congenital partial and complete absence of the pericardium. Mayo Clin Proc 1993;68:743–7.

Authors

Dr Matthew Morgan¹, Dr Abbas Ausami¹, Dr John Rawlins¹

1-University Hospital Southampton NHS Foundation Trust, Southampton, UK

Case history

88yo male presenting with exertional breathlessness and new murmur. Initially investigated with an echo which demonstrated severe aortic stenosis and moderate aortic regurgitation. As part of his work up for TAVI (transcatheter aortic valve implantation), he was referred for coronary angiography and CT coronary angiogram. The patient was found to have a congenital absence of his RCA, with the territory being supplied by a superdominant circumflex artery.

Figure 1 – 3D CTCA reconstruction of the heart from above, demonstrating single coronary origin off the left coronary cusp.Left image: heart and coronary vessels. Right image: coronary vessels with the heart subtracted.

Figure 2 – 3D CTCA reconstruction demonstrating the posterior heart, with a dominant circumflex wrapping round the atrioventricular groove to supply the RCA territory. Left image: heart and coronary vessels. Right image: coronary vessels with the heart subtracted.

Figure 3 – Left image: Coronary angiography demonstrating cannulation of the left mainstem with LAD descending vertically and dominant circumflex wrapping round to supply the RCA territory. Right image: 3D CTCA reconstruction of the coronary arteries demonstrating the same anatomy.

Multiple choice questions

Which of the following congenital abnormalities are associated with absent RCA?

1. Bicuspid aortic valve
2. Atrial septal defect
3. Aortic coarctation
4. Hypoplastic left heart syndrome
5. Tetralogy of Fallot

What is the most common symptom associated with absent RCA?

1. Wheeze
2. Sudden death
3. Asymptomatic
4. Palpitations
5. Shortness of breath

What is the approximate incidence of absent RCA in the general population?

1. 0.025%
2. 0.25%
3. 25%
4. 5%
5. 25%

Answers – 1,3,2

Discussion

Congenital absence of the RCA is a very rare anatomical variant with an estimated incidence of 0.014%-0.066%.¹Patients are usually asymptomatic and it is considered a benign pathology, although it can be associated with other cardiac abnormalities such as bicuspid aortic valve, coronary artery fistula and hypertrophic cardiomyopathy.² None of these were present in this case. Two patterns have been described: L-I pattern where the RCA territory is supplied by an extension of the circumflex artery or LAD (as in this case), and L-II pattern where the RCA territory is supplied by a branch arising from proximal LCA. The L-I pattern appears to be slightly more common and demonstrates a slightly higher incidence of acute MI.³

Previously coronary angiography was considered the gold standard of imaging, however with advances in CTCA, imaging with both modalities is considered useful in giving the most robust assessment of the coronary arteries and their neighbouring structures.³

There is no defined guideline for treatment, which may consist of either conservative or interventional management depending on the severity of coronary atherosclerosis and stenosis. In this case, the symptoms were all felt to be related to the patient’s severe aortic valve disease and he is being worked up for a TAVI.

References:

1. Zhu XY, Tang XH. Congenital absence of the right coronary artery: A case report. World J Clin Cases2022; 10(34): 12799-12803 [PMID: 36579109 DOI: 12998/wjcc.v10.i34.12799]
2. Canan, A. and Batra, K., 2022. Superdominant Left Circumflex Artery with Absent Right Coronary Artery. Radiology, 304(2), pp.294-294.
3. Chen Z, Yan J, Han X, Adhikari BK, Zhang J, Zhang Y, Sun J, Wang Y. Congenital absence of the right coronary artery with acute myocardial infarction: report of two cases and review of the literature. J Int Med Res. 2020 Dec;48(12):300060520971508. doi: 10.1177/0300060520971508. PMID: 33275472; PMCID: PMC7720338.