Systolic Anterior Motion After Mitral Valve Repair: Echocardiographic Prediction, Surgical Prevention and...

Systolic anterior motion (SAM) of the mitral valve remains a clinically relevant complication after mitral valve repair and may result in dynamic left ventricular outflow tract (LVOT) obstruction, SAM-associated mitral regurgitation, and hemodynamic instability. Despite advances in surgical techniques and perioperative imaging, SAM remains an important cause of difficult separation from cardiopulmonary bypass and postoperative circulatory compromise. The development of SAM is multifactorial and results from the interaction between mitral valve anatomy, ventricular geometry, surgical repair characteristics, and perioperative hemodynamic conditions. Contemporary evidence has identified several echocardiographic predictors, including excessive posterior leaflet height, elongated anterior leaflets, reduced coaptation-septal distance, a narrow mitro-aortic angle, basal septal hypertrophy, and small hyperdynamic left ventricles. Recognition of these risk factors facilitates perioperative risk assessment and pre-repair surgical planning. Transesophageal echocardiography plays a pivotal role throughout the perioperative period, enabling risk assessment before repair, early diagnosis after cardiopulmonary bypass, and guidance of therapeutic interventions. Initial treatment is based on preload optimization, afterload augmentation, withdrawal of inotropic stimulation, and heart rate control, whereas refractory cases may require surgical revision. This narrative review summarizes the current understanding of SAM after mitral valve repair, focusing on pathophysiological mechanisms, echocardiographic predictors, surgical prevention and perioperative management, with particular emphasis on the practical role of cardiac anesthesiologists and mitral valve surgeons.