冠状动脉结扎前后容量负荷对狗两心室功能的影响

本实验研究了狗左冠状动脉前降支(LAD)结扎前后,以动脉放血和静脉输液改变容量负荷(VL),对左、右心室功能的影响。结果表明,LAD 结扎前后,两心室舒缩性能和泵功能对 VL 改变的反应均有明显差别。提示,心肌梗塞后,降低 VL可改善左心室功能,应防止 VL 过重对心功能的不利影响。

COMPARATIVE STUDY ON INFLUENCE OF ALTERED VOLUME LOAD ON BIVENTRICULAR FUNCTION BEFORE AND AFTER CORONARY ARTERY LIGATION IN DOGS

In anesthetized and thoracotomized dogs the influence of altered volume load(VL)by means of arterial bleeding and venous transfusion on left and rightventricular function was studied before and after left an-terior descending coronary artery(LAD)ligation.Themyocardial ischemic size made by LAD ligationamounted to 35.2±1.4% of left ventricular(LV)mass.Before LAD ligation,decreased VL had no evi-dent influence on biventricular contractility and relaxa-tion,but could improve LV relaxation after ligation.In-creased VL before LAD ligation resulted in the increaseof LV contractility and relaxation and decrease of rightventricular(RV)contractility and relaxation,but re-duced LV contractility and relaxation and improved RVrelaxation after ligation.Although increased VL couldenhance biventricular pump function obviously afterLAD ligation,the increased range was lower than thatof before ligation.The results indicated that decreasedVL could reduce influence of RV on LV and improveLV function after myocardial nfarction and the harmful influence of volume overload on cardiac function should be prevented.