Systolic anterior motion after mitral valve repair: predicting factors and management.

PURPOSE: The aim of this study was to determine the mechanism of systolic anterior motion (SAM) after mitral valve (MV) repair by analyzing the clinical data of patients with MV repair.

METHODS: A total of 104 MV repairs were performed for patients with isolated degenerative posterior leaflet prolapse. Eight patients (7.7%) developed SAM with severe mitral regurgitation. We compared the preoperative and intraoperative findings of the two groups (8 patients in the SAM group, 96 in the non-SAM group) and reported the clinical courses of the SAM patients.

RESULTS: Preoperative left ventricular end-diastolic and end-systolic diameters were significantly smaller and the preoperative left ventricular ejection fraction was significantly greater in the SAM group than in the non-SAM group. The number of patients with a sigmoid septum and the number with anterior leaflet-septal contact (LSC) during diastole were significantly larger in the SAM group. Incidence of billowing posterior leaflet, prolapsed segments, and operative techniques were comparable for the two groups. SAM improved with correction of hemodynamic status in four patients. In four other patients secondary cardiopulmonary bypass was required to resolve SAM. SAM resolved with additional repairs in two patients, whereas the other two required MV replacement. Of the six patients in whom conservative treatment or re-repair was successful, one had recurrent SAM 3 months after surgery.

CONCLUSION: The sigmoid septum and LSC may predict SAM after MV repair. A strict follow-up is imperative for patients with persistent or recurrent SAM.