左房压力-容量环在急性心肌缺血时的变化

The change of left atrial pressure volume loop in the state of ischemia

目的 探讨左房压力 -容量环在急性心肌缺血时的变化 ,了解左房功能的改变。方法 在犬应用心导管技术记录对照状态和结扎冠状动脉前降支后左房压力曲线 ,应用超声心动图AQ技术同步测量左房容量 ,应用计算机处理资料 ,获得左房压力 -容量环。结果 正常的左房压力 -容量环为近似“∞”形双环 ,包括一个逆钟向的“A”环 ,代表左房主动收缩和松弛 ,占据心室舒张末期 ;一个顺钟向的“V”环 ,代表心房充盈和被动排空。缺血状态下 ,“A”环面积增加 ,表明缺血状态左房收缩功能加强 ,左房被动排空和左房压下降减缓 ,在“V”环上显示曲线顺钟向下移速度减慢。结论 在发生急性心肌缺血时 ,左房主动收缩功能增强 ,左房 -左室偶联功能发挥代偿作用。

Objective To assess the change of left atrial pressure volume loop and left atrial function in the state of ischemia.Methods In 10 dogs left atrial pressure by catheter and left atrial volume by echocardiography AQ technique were recorded,then left anterior descending (LAD) of the coronary arteries were ligated completely.Ten minutes later repeated the test.After that input both pressure and volume data to a computer with a special software,left atrial pressure volume loops built automatically.Results At control state,left atrial pressure volume loops like a '∞' shape double loop,named A loop and V loop.At ischemia condition,the area of A loop increases,shows the systolic function of left atrial increase.Conclusions At the state of acute myocardial ischemia,the systolic function of left atrial increases left atrial left ventricular function douple actively.