前壁心肌梗死患者左心室血流向量特点及其与收缩功能的关系

目的 应用血流向量成像( VFM)技术分析前壁心肌梗死(心梗)患者左心室涡流和血流向量特点及其与收缩功能的关系.方法 前壁心梗患者(心梗组)31例,对照组20例.记录心尖三腔心彩色多普勒二维图像,VFM技术观察各心动时相左心室涡流和血流速度向量特点.结果 (1)两组在等容收缩期左心室腔内均可见整体涡流;心梗组收缩期及舒张期左心室内均存在涡流,对照组收缩期未见涡流,舒张期左室内可见短暂、局部涡流.(2)心梗组快速射血期心尖部及中部血流速度方向朝向心尖,与基底部血流方向相反,也与对照组相反(10.6±8.3) cm/s比-(5.8±7.2)cm/s,(19.5±11.8) cm/s比-(16.6±14.7) cn/s];快速充盈期心尖部血流速度低于对照组(6.8±9.8) cm/s比(17.6±15.8)cm/s,P＜0.01].(3)心梗组心尖部快速射血期血流速度与左心室射血分数(LVEF)呈负相关(r= -0.52,P＜0.05).心梗组LVEF＜ 50％患者快速射血期心尖部血流速度高于LVEF≥50％患者(13.5±9.0) cm/s比(5.8±5.1) cm/s,P＜0.01].结论 前壁心梗患者左心室内涡流持续时间较对照组延长,心梗组快速射血期心尖部及中部血流向量方向朝向心尖,心尖部血流速度与LVEF呈负相关.

Left ventricular flow vector characteristics and the relationship between flow vector and left ventricular systolic function in patients with anterior myocardial infarction

Objective To assess left ventricular vortex and flow vector features and the relationship between vector flow and left ventricular systolic function in patients with anterior myocardial infarction by echocardiography-derived vector flow mapping (VFM).Methods Echocardiography was performed in 31patients with anterior myocardial infarction and 20 healthy controls.Flow vector and velocity of left ventricle were analyzed on apical 3 chambers view with color Doppler.Results ( 1 ) Left ventricular intracavitary vortex during isovotumic contraction phase could be detected in both groups.Vortex was detectable also during contraction phase and relaxation phase in patients with myocardial infarction.There was no vortex during contraction phase,and there was only small and transit vortex during relaxation phase in control group.(2)Flow vector of apex and middle segments directed to apex and was opposite to that of basal segment of left ventricle in patients with myocardial infarction and in controls ( 10.6 + 8.3 ) cm/s vs.- (5.8 ±7.2) cm/s,( 19.5 ± 11.8) cm/s vs.- ( 16.6 ± 14.7) cm/s].During rapid relaxation phase,the velocity in apex was lower in patients with myocardial infarction than that in control group (6.8 ±9.8)cm/s vs.( 17.6 ± 15.8) cm/s,P ＜0.O1 ].(3)There was a negative correlation between velocity in apex and left ventricular ejection fraction (LVEF) during rapid eject phase in patients with anterior myocardial infarction (r = - 0.52,P ＜ 0.05 ).Velocity in apex of patients with LVEF ＜ 50％ was higher than that of patients with LVEF≥50％ during rapid eject phase (13.5 ±9.0) cm/s vs.(5.8 ±5.1) cm/s,P ＜0.05 ].Conclusions Vortex period is prolonged in patients with anterior myocardial infarction compared to normal controls during whole cardiac cycle,flow vector of apex and middle segments is directed to apex during eject phase and there is a negative correlation between velocity in apex and LVEF during rapid eject phase in patients with anterior myocardial infarction.