Midventricular Obstruction Caused by Abnormal Intra-Left Ventricular Septum and Papillary Muscles.

Abnormal papillary muscle is a rare cause of midventricular obstruction. In this case report, hypertrophied abnormal papillary muscles and abnormal tissue growth from the septal wall formed an intra-left ventricular septum with a small hole and resulted in severe midventricular obstruction. Radical resection of both papillary muscles and the intra-left ventricular septum was performed along with mitral valve replacement to relieve the obstruction.