左室急性心肌缺血对右心功能影响的超声组织速度成像研究

目的:应用组织速度成像(TVI)技术研究犬左室急性心肌缺血状态下右心功能的变化特点及其相互关系.方法:10只犬行右冠状动脉前降支结扎,制作急性心肌缺血模型,分别于冠状动脉左前降支结扎前、后10min采集心尖四腔切面图像,测量缺血前后右室壁、右房壁及三尖瓣环的收缩期峰值速度(Vs)、舒张早期峰值速度(Ve)、舒张晚期峰值速度(Va)、右室射血分数(RVEF),用导管法测肺动脉收缩压(PASP).结果:与缺血前比较,左室局部急性心肌缺血后PASP增加(P＜0.05),RVEF降低(P＜0.05),右室壁和三尖瓣环的Vs、Ve及Va降低(P＜0.05),右房壁Vs和Va增加(P＜0.05).心肌缺血前,右室壁与右房壁的运动速度无明显相关性;心肌缺血后两者呈负相关,RVEF与右室壁及三尖瓣环的Vs均呈正相关,PASP与RVEF呈负相关.结论:急性心肌缺血可引起右室壁运动功能减退,右房壁运动功能代偿性增加.

A Study on right heart function in acute myocardial ischemia of left ventricle by tissue velocity imaging

Objective: To study the changes of right heart function of dogs by tissue velocity imaging(TVI) after the left ventricular acute myocardial ischemia.Method: Ten dogs were subjected to LAD coronary artery occlusion for acute ischemia.Peak tissue velocity of systole(Vs),early diastole(Ve),and late diastole(Va) in right heart myocardial wall,the tricuspid annulus and right ventricular ejecting fraction(RVEF) were measured and catheter-measured systolic pressure of pulmonary arteria(PASP) were measured at pre and post legation LAD,respectively.Results: PASP were increased(P<0.05).RVEF were decreased(P<0.05).Vs,Ve,Va of the right ventricle and the tricuspid annulus were significantly decreased(P<0.05) after myocardium ischemia.The Vs,Va of right atrial wall were increased(P<0.05).RVEF was positively correlated with Vs of the right ventricle and the tricuspid annulus at post-ischemia.Vs,Va of the right ventricle were not correlated with Vs,Va of the right atrial wall at pre-ischemia.Vs,Va of the right ventricle negatively correlated with Vs,Va of the right atrial wall and PASP negatively correlated with RVEF at post-ischemia.Conclusion: Acute myocardial ischemia of LV can lessen the right ventricular wall function.Right atrial wall compensatory increase in movement function.