安克律对麻醉犬程序性电刺激诱发性心律失常的影响

以程序性电刺激法研究安克律对犬心电生理和诱发性室性心律失常的影响。安克律引起血浓依赖性心室不应期延长和舒张期阈刺激强度增高,使QRS加宽,Q-Tc延长,高血浓使自发心率减,平均动脉血压降低。以双极电极行诱发刺激时,10例中半数可重复引起诱发性室性心律失常。然以阴极单电极行诱发刺激,则未能引起可重复的诱发性室性心律失常。表明在一定实验条件下,安克律可有易化诱发性室性心律失常的作用。

Effects of Encainide on the Inducibility of Ventricular Arrhythmia in Normal Anesthetized Dogs

Effects of encainide on electrophysiologic variables and ventricular arrhythmia inducibility were studied in normal anesthetized dogs,using programmed electrical stimulation with unipolar eathodal (8 dogs) or bipolar (10 dogs) stimulation modes.Encainide produced significant concentration-dependent increases in ventricular refractory period,and diastolic current threshold with smaller but significant increases in QRS and Q-Tc.It decreased spontaneous heart rate and mean arterial pressure at high concentration.After administration of encainide,ventricular tachyarrhythmias could be induced by bipolar stimulation in half of the dogs (5/10 dogs,P<0.05 compared to control),while unipolar eathodal stimulation could not cause reproducible ventricular arrhythmias.We conclude that encainide may facilitate the induction of ventricular arrhythmias in normal dogs and that bipolar stimulation may produce different results compared to unipolar stimulation in the presence of encainide.