Department of Surgery and Cancer, Imperial College London, London, UK.
Eur J Cardiothorac Surg. 2012 Jun;41(6):1260-70. doi: 10.1093/ejcts/ezr232. Epub 2012 Jan 18.
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.
二尖瓣前向运动（SAM）可能是一种危及生命的情况。SAM 可导致严重的左心室流出道梗阻和/或二尖瓣反流，并伴有高达 20%的猝死风险（在肥厚型心肌病（HCM）中风险要低得多）。SAM 的机制很复杂，取决于心室的功能状态。SAM 可发生在正常人群中，但通常见于 HCM 患者或二尖瓣修复后。超声心动图（2D、3D 和应激）具有核心诊断作用，因为应用超声心动图 SAM 预测因子可在手术期间和术后 SAM 评估中纳入预防技术。心脏磁共振成像在了解 SAM 的动态性质方面具有特殊作用，尤其是在解剖结构非典型的心脏（包括 HCM）中。本文介绍了临床医生需要了解的关于 SAM 的信息，包括病理生理机制和影像学方法，以及保守（药物）和手术方法及其各自的结果。提倡采用逐步方法，包括药物治疗，随后进行积极的容量负荷和β肾上腺素能受体阻滞剂治疗。手术是最后的选择。正确选择手术技术需要了解 SAM 的解剖学基础。
