Delayed-Onset Systolic Anterior Motion of the Mitral Valve After Aortic Valve Replacement for Severe Aortic Stenosis

Systolic anterior motion (SAM) of the mitral valve after aortic valve replacement (AVR) for severe aortic stenosis (AS) is one of the causes of perioperative left ventricular outflow tract (LVOT) obstruction in older patients. A 90-year-old woman underwent AVR with a 19-mm bioprosthesis for symptomatic aortic valve stenosis. Preoperative transthoracic echocardiography (TTE) showed left ventricular hypertrophy, with LVOT obstruction and mild mitral regurgitation (MR). Intraoperative transesophageal echocardiography and postoperative TTE showed that the degree of MR was unchanged after surgery. The patient's postoperative course was uneventful. However, she developed shortness of breath 6 months after discharge. A subsequent TTE showed significant LVOT obstruction and SAM, which resulted in moderate to severe MR. Because of the patient's advanced age, cibenzoline was administered to decrease the left ventricular pressure gradient (LVPG) and improve the left ventricular diastolic function. Two months after administration of cibenzoline, a TTE showed decreased LVPG, trivial MR, and the absence of SAM. This case clearly demonstrated that cibenzoline improved the SAM of the mitral valve that arose after AVR for AS in a remote postoperative period.