ABSTRACT
Introduction Coronary artery fistulas are connections between one or more of the coronary arteries and a cardiac chamber or great vessel. They are rare but are the commonest hemodynamically significant coronary artery abnormality, and usually occur in isolation.1 Although usually congenital, they have been noted after cardiac surgery, such as valve replacement, coronary artery bypass grafting, and after repeated myocardial biopsies in cardiac transplantation.2,3
The fistula tends to be a dilated, long, and tortuous artery taking a course around the heart before terminating in a chamber or a vessel. It may drain from a main coronary artery or one or several branches of a coronary artery to a cardiac chamber or into a nearby vessel. Multiple feeding arteries to a single coronary artery fistula may exist.2 More than 55% of the fistulas originate from the right coronary artery, with the left anterior descending coronary artery being the next most frequently involved.4 Over 90% of the fistulas from either coronary artery drain to the right side of the heart. The remainder drain to either the left atrium or the left ventricle.5
