[Mitral Valve Replacement with a Low-Profile Bioprosthesis in Combination with Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy;Report of a Case].

An 83-year-old woman diagnosed with hypertrophic obstructive cardiomyopathy was referred to our hospital. Her echocardiogram revealed diffuse left ventricular hypertrophy, severe mitral valve regurgitation with systolic anterior motion of the mitral valve, and left ventricular obstruction with a peak outflow gradient of 142 mmHg. Cardiac catheterization revealed a peak pressure gradient of 60 mmHg across the left ventricular outflow tract. Because of the patient's advanced age, as well as uncertainty regarding our ability to resolve her mitral regurgitation, we performed mitral valve replacement with a St. Jude Medical Epic porcine low-profile bioprosthesis in combination with septal myectomy. The patient's postoperative course was uneventful. At 1 year after the operation, her functional status was New York Heart Association class I. The echocardiogram showed the peak outflow gradient markedly decreased to 9 mmHg.