Hypertrophic cardiomyopathy with anteriorly-directed mitral regurgitation is a red flag for concomitant pathology - A Case Report

Abstract Background Hypertrophic cardiomyopathy (HCM) is often linked to systolic anterior motion (SAM) of the mitral valve, typically resulting in a posteriorly directed mitral regurgitation (MR) jet. An anteriorly directed MR jet suggests additional mitral valve pathology that may not be resolved by myectomy alone. Case Summary A 58-year-old construction worker with no significant medical history experienced a syncopal event and was admitted to the emergency department with acute pulmonary oedema. A systolic murmur was investigated with a transthoracic echocardiogram (TTE) which revealed severe MR with an unusual anteriorly directed MR jet and a possible flail segment of the posterior leaflet. This finding was further characterised with a trans-oesophageal echocardiogram (TOE) which revealed severe asymmetric septal hypertrophy with SAM of the mitral valve, severe mitral regurgitation into a dilated left atrium with pulmonary vein flow reversal not caused by HCM-associated SAM, and a markedly abnormal mitral valve with flail and prolapse. The patient underwent successful cardiac surgery, including mitral valve repair and septal myectomy. The patient's recovery was uneventful, allowing for a return to work within a month post-surgery. Discussion The anteriorly directed MR jet served as a red flag, leading to the discovery of an independent mitral valve pathology that required surgical intervention beyond the expected treatment for SAM-associated HCM. This case highlights the complexity of assessing MR in patients with HCM and underscores the importance of characterising MR jet direction in diagnosing additional mitral valve diseases.