Post-mitral valve repair systolic anterior motion produced by non-obstructive septal bulge

Abstract

Objective: Systolic anterior motion (SAM) may rarely occur after mitral valve reconstruction due to different anatomic factors. Several techniques have been described to reduce the incidence of post-repair SAM, e.g. leaflet sliding plasty. However, SAM can still occur after these special procedures. We reviewed data of patients developing SAM with significant mitral regurgitation due to non-obstructive septal bulge. Methods: During a 2-year period mitral valve repair was performed in 358 patients. Five of 358 (1.4%) patients with a mean age of 52±10.5 years developed post-repair SAM with severe mitral insufficiency due to non-obstructive septal bulge. Data of these patients were analyzed retrospectively and controlled after a mean follow-up of 18±2.7 months. Results: Preoperative echocardiography showed end-diastolic septum diameter of 7, 10, 10, 11 and 15 mm. The ratio between end-diastolic septum diameter and free wall diameter was 1 in four patients and 1.25 in one patient. There was no left ventricular outflow tract obstruction (LVOT). Intraoperative data revealed large myxomatous anterior (four patients) and posterior (three patients) leaflets. Quadrangular resection of posterior leaflet was carried out in four patients and sliding plasty in one patient. Cause for post-repair mitral regurgitation was a non-obstructive septal bulge. During a second pump run septal bulge was resected. Mean aortic cross-clamp time and cardiopulmonary bypass time for this procedure was 15±1.4 and 28±3.1 min, respectively. Mitral regurgitation disappeared in all patients immediately after this procedure. The grade of mitral regurgitation at follow-up was 0-1 in all patients. One patient had subaortic gradient of 36 mmHg. Conclusions: If mitral regurgitation occurs after primary successful mitral repair, septum bulge should always be considered as the primary cause for SAM even there is no preoperative gradient in LVOT. Before performing time-consuming corrective operations to relieve SAM, a septum resection should be carried out during a short second pump run. © 2003 Elsevier B.V. All rights reserved.