主动脉瓣置换术后SAM现象机制及相关因素的探讨

The mechanism and correlative factors of SAM syndrome after aortic valve replacement

目的 探讨主动脉瓣置换术后SAM现象的发生机制并对其相关因素进行分析 ,旨在进一步认识此现象。方法 4 8例严重主动脉瓣狭窄病人 ,男 2 6例 ,女 2 2例 ;年龄 2 0～ 5 8岁。行主动脉瓣置换术后 1周内复查超声心动图 ,以是否出现SAM现象分成两组 ,对左室舒张末期内径、收缩末期内径、左室流出道内径、室间隔和左室后壁厚度、左室流出道射流速度及压力阶差进行对比。结果 无手术死亡。 9例左室流出道流速显著增加 (大于 2 5m s) ,其中 6例出现了SAM现象。除左室后壁对比差异无显著性外 ,其余指标对比差异均具显著性 (P <0 0 5或 0 0 1)。结论 主动脉瓣置换术后出现SAM现象与左室流出道流速和压力阶差增大有直接关系 ,而小左室舒张末期内径、收缩末期内径、流出道内径及增厚的室间隔是SAM现象的主要病理解剖基础。

Objective: To investigate the mechanism and correlative factors of SAM syndrome after aortic valve replacement. Methods: 48 patients with severe aortic valve stenosis were studied, echo-Doppler study was performed one week after aortic valve replacement, and the patients were divided into two groups with or without SAM Syndrome. The left ventricular end-diastolic dimensions, the left ventricular end-Systolic dimensions, the left ventricular outflow tract the thickness of septum and posterior wall, the maximal left ventricular velocities and left intra-ventricular dynamic gradients were recorded and compared. Results: There was no operative mortality. The maximal left ventricular velocities were increased significantly in 9 patients (more than 2。5 m/s) and six of them had SAM syndrome. There were statistic significance (P<0。05 or P<0。01) except the posterior wall of left ventricular. Conclusion: The occlusion of SAM syndrome after aortic valve replacement related to the increase of maximal left ventricular velocities and systolic intracavitary gradients, and the smaller systolic and diastolic diameters of the left ventricle and hypertrophy of septum were anatomy basis of SAM syndrome.