High-Output Heart Failure due to a Giant Left Circumflex Coronary Aneurysm with a Left Atrial Fistula and Atrial Septal Defect: A Case Report

A coronary artery aneurysm is a rare cardiac anomaly that may be incidentally detected on echocardiography. When associated with a coronary cameral fistula, an aneurysm can become symptomatic. We present a unique case of a giant left circumflex coronary aneurysm with a fistula to the left atrium and a large atrial septal defect causing acute heart failure in a young woman during the peripartum period.