Modern management of systolic anterior motion of the mitral valve

Abstract

Systolic anterior motion (SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)). The mechanisms of SAM are complex and depend on the functional status of the ventricle. The SAM can occur in the normal population, but is typically observed in patients with HCM or following MV repair. Echocardiography (2D, 3D and stress) has a central diagnostic role as the application of echocardiographic SAM predictors allows the incorporation of prevention techniques during surgery and post-operative SAM assessment. Cardiac magnetic resonance imaging has a special role in understanding the dynamic nature of SAM, especially in anatomically atypical hearts (including HCM). This article describes what the clinician needs to know about SAM ranging from pathophysiological mechanisms and imaging modalities to conservative (medical) and surgical approaches and their respective outcomes. A stepwise approach is advocated consisting of medical therapy, followed by aggressive volume loading and beta-adrenoceptor blockade. Surgery is the final option. The correct choice of surgical technique requires an understanding of the anatomical substrate of SAM.

Left ventricular outflow tract obstruction in ICU patients

“…Myocardial infarction can induce LVOTO [23,24]. The mechanism of dynamic LVOTO in this setting is compensatory hyperkinesis of preserved myocardial segments.…”

Severe Systolic Anterior Motion After Aortic Valve Replacement and Cox MAZE Surgery

“…5 However, in our case we failed to improve the hemodynamic condition medically, and replacement of the mitral valve was then performed.…”

Left Ventricular Outflow Tract Obstruction after Ross-Konno Operation

“…Any changes in these functional units can contribute to SAM [2]. The mitral valve of SAM may appear in a life-threatening case of hypertrophic cardiomyopathy by causing dynamic LVOT obstruction, after cardiac surgery including especially mitral valve surgery and after a variety of medical and metabolic conditions [2].…”

“…Systolic anterior motion (SAM) related to left ventricular outflow tract obstruction (LVOTO) can vary from causing clinically silent disease to severe LVOTO in a diversity [2].…”