Abstract 14694: Coronary Artery Fistula Presenting With Complete Heart Block and Syncope

Abstract

Introduction: Coronary artery fistula (CAF) is an anomalous connection between one or more coronary arteries and a cardiac chamber or great vessel. The incidence of coronary fistulas is estimated to be 0.2-0.4% of all cardiac malformations. We present a 75 year old female who presented with a complete heart block, which was most likely caused by a fistula between the coronary vasculature and the pulmonary trunk. Clinical presentation: A 75 year old female with a past medical history of hypertension, hyperlipidemia, and COPD presented with two episodes of syncope. Clinical examination was unremarkable. The EKG showed complete third degree heart block requiring transcutaneous pacing. Echocardiography showed normal left ventricular size and function, with an ejection fraction of 55%. The right ventricle size and function were also normal. No hemodynamically significant valvular disease was seen. Left heart catheterization showed occluded middle right coronary artery, 50% stenotic lesion in the left anterior descending artery (LAD), and an abnormal termination of the first diagonal branch of the LAD (D1) into the pulmonary trunk indicative of a fistula. The fistula was the presumed cause of the complete heart block in this patient. The fistula was managed by observation rather than surgical intervention while a dual chamber pacemaker was placed to address the complete heart block. Conclusions: Coronary artery fistulas are either congenital or acquired. They are rare and usually asymptomatic but can present with a myriad of symptoms. Our case describes a patient presenting with complete heart block and syncope, with a fistula detected on coronary angiography. This is considered the gold standard for diagnosing CAF. Disrupted coronary flow leading to ischemic complete heart block is the presumed process leading to syncope in this patient. Other modalities that can assist in this diagnosis include echocardiography, computed tomography, or magnetic resonance imaging.