Surgical Management of Hypertrophic Obstructive Cardiomyopathy

Hypertrophic cardiomyopathy is an inherited disease, transmitted as an autosomal dominant, that affects cardiac myocytes. It most commonly affects middle-aged adults, producing asymmetric hypertrophy of the interventricular septum. Hemodynamically, this results in obstruction of the left ventricular outflow tract (LVOT) and mitral regurgitation caused by systolic anterior motion (SAM) of the anterior mitral leaflet. Patients typically experience symptoms attributable to congestive heart failure, arrhythmia, or angina. Patients refractory to medical management who have important resting LVOT obstruction are candidates for surgical management. The Morrow type septal myectomy abolishes SAM and reduces LVOT gradient in the majority of patients. We suggest mitral valve replacement be reserved for those patients having both nontrivial intrinsic mitral valve disease and hypertrophic obstructive cardiomyopathy. Dual-chamber pacing has been recently introduced as a treatment modality; pacing can be useful in symptomatic patients with labile outflow tract obstruction, but long-term follow-up is lacking.