Clinical introduction

A 57-year-old man from the USA with a history of atrial fibrillation and hypertension was evaluated for progressive dyspnoea and decreased energy. The patient denied a history of congestive heart failure, systemic symptoms or myocardial infarction. He was found to have a 3/6 holosystolic murmur radiating to the axilla. Transthoracic echocardiography (TTE) reported a reduced ejection fraction of 40%, mitral valve regurgitation and absence of interatrial shunts. The remaining cardiac valves were without abnormality. A nuclear stress test reported 18% fixed inferolateral defect. Subsequent coronary angiography was negative for obstructive coronary artery disease. To better …