Right Coronary Artery-Superior Vena Cava Fistula Manifesting as NSTEMI: Case Report, Review of Imaging, and Summary of Guidelines

Coronary artery fistulas (CAFs) represent a spectrum of abnormal connections between a coronary artery and another coronary artery, vein, or major blood vessel, known as coronary-vascular fistulas, or between a coronary artery and a cardiac chamber, known as coronary-cameral fistulas. While CAFs generally remain asymptomatic into the fifth decade of adult life, they can present with a diverse symptomatic profile, typically with angina from abnormal myocardial perfusion, or in the setting of larger fistulas, as right- or left-heart failure from pulmonary or left ventricular circulatory overload. CAFs rarely manifest as myocardial infarction in the absence of thrombosis within the fistula. When clinically suspected based on a continuous murmur on physical exam or an accidental finding on radiology, computed tomography angiography (CTA) and coronary angiography are the preferred diagnostic imaging modalities. Fistula anatomic and patient specific characteristics guide clinical decisions on transcatheter or surgical management strategies. We present the case of a right coronary artery-superior vena cava fistula manifesting as a non-ST elevation myocardial infarction. We also present a review of the imaging techniques available for evaluation of CAFs, and a summary of the major national and international cardiology society guidelines on the diagnosis and management of CAFs.