Multivessel Coronary Artery Fistula Presenting as Coronary Steal Syndrome Leading to Cardiac Arrest

The coronary steal phenomenon refers to myocardial ischemia caused by the diversion of blood away from normal myocardial circulation. A coronary artery fistula (CAF) is an abnormality of the coronary anatomy characterized by the aberrant termination of a coronary artery or its branches into cardiac chambers or great vessels. Although CAFs are often thought to be asymptomatic, fistulas that diverge a significant amount of blood flow and decrease the normal perfusion of myocardial tissue can cause ischemia and can present with acute coronary syndrome. We describe a unique case of a 70-year-old woman with no coronary artery disease (CAD) undergoing ventricular fibrillation and sudden cardiac arrest from myocardial ischemia secondary to coronary steal brought on by multivessel CAFs. This case was unique in that fistulas originating from the left anterior descending and from the circumflex artery draining into the left heart chambers are the least frequently observed. To our knowledge, only two other reports in the literature, demonstrating sudden cardiac arrest in patients with left anterior descending to left ventricle fistulas with no CAD, exist. The case presented, along with the literature reviewed, demonstrates that CAFs may be an important part of the differential diagnosis of symptoms of chest pain and myocardial ischemia, particularly in middle-aged adults with no history of coronary artery disease or related comorbidities.