早搏后强化作用评定心肌收缩性

AN EVALUATION OF CARDIAC CONTRACTILITY WITH THE POSTEXTRASYSTOLIC POTENTIATION

应用心脏程序刺激仪经右心房诱发早搏,以早搏后与早搏前心搏左心室压力最大变化速率的比值(RLV+dp/dtmax)为指标,观察10只麻醉狗的左心室早搏后强化作用(PESP)。随着早搏联律间期的缩短或(和)早搏代偿间期的延长,RLV+dp/dtmax逐渐增大;RLV+dp/dtmax在快速输注低分子右旋糖酐时保持不变,注射多巴酚丁胺时显著降低,结扎左冠状动脉前降支后明显增大。表明在早搏时间间期相同条件下比较应用。

With the ratio of the largest changing rate of the postextrasystole and preextrasystole as an index, the postextrasystolic potentiation (PESP) of the left ventricle was examined in 10 anesthetized dogs by artificially induced extrasystole via right atrium with a cardiac programming irritating instrument. With the shortening of the extra-systolic interval and the lengthening of the extrasystolic compensatory interval, RLV+dp/dt max was gradually increased. RLV + dp/dt max was not altered by the rapid infusion of Dextran. When dobutamine was injected, the ratio is obviously lowered, but after the ligation of the anterior descending branch of the left coronary artery, it was obviously. increased. These results suggest that under the same condition of the extrasystolic interval, PESP is a reliable method to evaluate the cardiac contractility.