Pseudo Systolic Anterior Motion: Potential for Severe Mitral Regurgitation after Aortic Valve Replacement

A 68-year-old man with severe aortic stenosis (AS) and marked left ventricular hypertrophy (LVH), underwent aortic valve replacement (AVR). Preoperative echocardiography demonstrated contact between the anterior mitral leaflet and the interventricular septum during diastole without mitral regurgitation (MR), i.e., "pseudo systolic anterior motion (SAM)." After a mechanical prosthesis had been implanted, severe mitral regurgitation MR and pulmonary hypertension occurred due to "true" SAM of the mitral valve. Despite intensive management, it was difficult to control MR in the acute phase. In the chronic phase, echocardiography revealed the resolution of both SAM and MR. It is suggested that the dramatic reduction of afterload after alleviation of valvular stenosis by prosthetic replacement and increased flow velocity in the left ventricular outflow tract (LVOT) caused SAM with MR. The risk of SAM after AVR should be considered in AS patients with marked LVH, especially in the presence of "pseudo SAM."