When Intraoperative Hypotension Is Not What It Seems: Systolic Anterior Motion of the Mitral Valve Causing Severe Hypotension During Noncardiac Surgery.

Intraoperative hypotension in noncardiac surgery is common and often multifactorial. We report a case of refractory hypotension during orthopedic surgery initially suspected to represent massive pulmonary embolism based on tachycardia and reduced end tidal carbon dioxide. Rescue transesophageal echocardiography demonstrated hyperdynamic biventricular function without right ventricular strain and identified systolic anterior motion of the mitral valve with dynamic left ventricular outflow tract obstruction and posteriorly directed mitral regurgitation. Targeted management with volume expansion, afterload augmentation, and beta blockade resulted in rapid hemodynamic improvement, highlighting systolic anterior motion as an underrecognized and reversible cause of intraoperative hypotension.