CASE 16878 Published on 13.07.2020

Teaching Case

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Sameh Khalil, MD¹^,2, Taher Moustafa BSc¹, Ahmed Hamdy, BSc¹, Sara Ragab, BSc¹, Omnia Mohammed BSc¹, Esraa Maher, BSc¹, Amina Atef, BSc¹, Shaymaa Ahmed MSc¹, Ahmed Heny MSc¹ and Maha Taher, MD¹.

1. Alfa Scan Radiology Center, Cardiovascular imaging department, Cairo, Egypt.

2. Radiology Department, Ain Shams University hospital, Cairo, Egypt.

Patient

48 years, male

Categories

Area of Interest Cardiac ; Imaging Technique MR, MR-Angiography ;

No Procedure ; No Special Focus ;

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Clinical History

A 48-year-old patient presented with exertional chest pain. Normal ECG. Echocardiogram revealed a large vascular structure originating from the left coronary sinus corresponding to the left coronary artery, echocardiography suggested coronary aneurysm. Also, it suggested increased left ventricular trabeculation.

Differential Diagnosis List

Coronary arteriovenous fistula.

LCx aneurysm.

Coronary vasculitis (Takayasu).

Imaging Findings

Patient was referred to CMR for non-compaction cardiomyopathy versus an infarcted dilated segment. CMR revealed That the facing sinus 2 (left coronary sinus) is seen giving origin to a patent dilated caliber LM coronary artery (18 mm diameter) that is seen bifurcating into an average caliber LAD and dilated LCx (15 mm diameter), the distal LCx is seen connected to coronary sinus with arteriovenous fistula measuring +/- 10 mm at its narrowest diameter, consequent dilated and tortuous coronary sinus. No appreciable on top thrombi.

There was a consequent dilated left ventricle with EDVI 141 ml/ m2 (normal age and sex-matched EDVI is 64-100 ml/ m2) and dilated right ventricle with EDVI 133 ml/ m2 (normal age and sex-matched EDVI is 63-111 ml/ m2).

Discussion

Coronary arteriovenous fistulas are abnormal connections of coronary arteries with venous system bypassing the normal capillaries within the myocardium. Most affected patients are asymptomatic early, yet, symptoms and complications develop with increasing age (1).

Treatment options are surgical ligation or percutaneous transcatheter closure (2).

The pathophysiology of a coronary arteriovenous fistula depends on the resistance of the fistulous connection at the site of fistulous termination.

Dedicated imaging checklist includes the origin and drainage site and number of fistulous communications (single or multiple), the size of narrowest point in the fistulous connection (1).

Imaging options are conventional coronary angiography which is diagnostic and therapeutic (3). ECG gated CT, Echocardiography with contrast agents and CMR which are not invasive modalities (1).

CMR may be an alternative to conventional and CT coronary procedures (best two imaging modalities) particularly in children and individuals who need a repeated follow-up imaging, because it does not use ionizing radiation or iodinated contrast material. Yet, it has lower spatial resolution and contrast-to-noise ratio and takes longer to perform. It has a limited role in tracing the course of distal coronary arteries (4 and 5)

Coronary arteriovenous fistulas can affect the hemodynamic condition like in our case who presented with bi-ventricular consequent dilatation (6). Other multiple complications include myocardial ischemia, heart failure, arrhythmia, and infective

endocarditis (7).

The treatment plan for this patient was percutaneous transcatheter closure as there was a single site of drain with distal portion of fistula accessible with the closure device and absent concomitant cardiovascular anomalies, it was a simple uncomplex fistula, there was no risk for large vessel accidental embolization.

Teaching point

Although it is not the first modality of choice, CMR can help in depicting hidden coronary arteriovenous fistulas and detecting its complications like myocardial hemodynamic effect, ischemia and infarctions.

References

[1] Yun G, Nam T and Chun MS. Coronary Artery Fistulas: Pathophysiology, Imaging Findings and Management. RadioGraphics 2018; 38:688–703.

[2] Minhas AM, Ul Haq E, Awan AA, Khan AA, Qureshi G, Balakrishna P. Coronary-cameral fistula connecting the left anterior descending artery and the first obtuse marginal artery to the left ventricle: a rare finding. Case Rep Cardiol 2017;2017:8071281.

[3] Reddy G, Davies JE, Holmes DR, Schaff HV, Singh SP, Alli OO. Coronary artery fistulae. Circ Cardiovasc Interv 2015;8(11):e003062.

[4] Shabestari AA, Akhlaghpoor S, Fatehi M. Findings of bilateral coronary to pulmonary artery fistula in 64-multislice computed tomographic angiography: correlation with catheter angiography. J Comput Assist Tomogr 2008;32(2):271–273.

[5] Buccheri D, Luparelli M, Chirco PR, Piraino D, Andolina G, Assennato P. A call to action for an underestimated entity: our algorithm for diagnosis and management of coronary artery fistula. Int J Cardiol 2016;221:1081–1083.

[6] Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990;21(1):28–40.

[7] Vitarelli A, De Curtis G, Conde Y, et al. Assessment of congenital coronary artery fistulas by transesophageal color Doppler echocardiography. Am J Med 2002;113(2):127–133.

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