Another pitfall in minimally invasive mitral valve repair.

We report a case of severe systolic anterior motion (SAM) and dynamic left ventricular outflow obstruction after repair of a flail posterior leaflet of the mitral valve. The reason for SAM was found to be due to traction on the pericardial stay sutures placed to expose the surgical field. The SAM and the outflow obstruction were completely resolved by cutting these sutures. Our case demonstrates the contribution of geometric factors in the development of SAM and left ventricular outflow obstruction and emphasizes the need to evaluate the heart in its natural position within the mediastinum.