We present a case of previously undiagnosed hypertrophic obstructive cardiomyopathy (HOCM) with left ventricular outflow obstruction in a woman anesthetized for lumbar hemilaminectomy and diskectomy. The treatment of her sudden unexplained hypotension was initially confounded by a diagnosis of compensated congestive heart failure and diuretic therapy. Swift intervention with transesophageal echocardiography revealed the tru pathology altering her intraoperative treatment and her subsequent chronic treatment for her heart condition.