Inoue H, Murakawa Y, Toda I, Nozaki A, Matsuo H, Mashima S, Sugimoto T
Am Heart J. 1986 Jun;111(6):1080-7. doi: 10.1016/0002-8703(86)90009-8.
We studied the epicardial activation sequence during torsade de pointes in canine hearts with quinidine-induced long QT interval. Following a toxic dose of quinidine sulfate (30 mg/kg), polymorphic ventricular tachycardia was induced by extrastimuli. In nine dogs, 22 episodes of nonsustained polymorphic ventricular tachycardia and six episodes of monomorphic ventricular tachycardia were induced. Of 22 episodes of nonsustained polymorphic ventricular tachycardia, 12 episodes showed typical torsion of the spikes of the QRS complex around the isoelectric line (torsade de pointes). Isochronal maps were made from 38 simultaneously recorded bipolar electrograms and showed that each change in QRS morphology was associated with a change in the earliest epicardial activation site and/or a change of epicardial activation sequence. During episodes of torsade de pointes, the earliest epicardial activation site migrated gradually from one site to another site. The transitional QRS complexes had their earliest epicardial activation sites between the new and old site of the earliest epicardial activation. The changes in the earliest epicardial activation site during polymorphic ventricular tachycardia without torsade de pointes pattern was not as great as that noted during torsade de pointes. This study suggests that in a noninfarcted canine model torsade de pointes is produced by alteration in the earliest site of activation rather than by competition from two or more competing foci.
我们研究了奎尼丁诱发长QT间期的犬心在尖端扭转型室速期间的心外膜激动顺序。给予硫酸奎尼丁中毒剂量（30mg/kg）后，用期外刺激诱发多形性室性心动过速。在9只犬中，诱发了22阵非持续性多形性室性心动过速和6阵单形性室性心动过速。在22阵非持续性多形性室性心动过速中，12阵表现出QRS波群的波峰围绕等电线典型扭转（尖端扭转型室速）。根据38个同步记录的双极电图绘制等时图，结果显示QRS形态的每一次改变都与最早的心外膜激动部位改变和/或心外膜激动顺序改变相关。在尖端扭转型室速发作期间，最早的心外膜激动部位逐渐从一个部位移至另一个部位。过渡性QRS波群的心外膜最早激动部位位于最早心外膜激动的新旧部位之间。无尖端扭转型室速图形的多形性室性心动过速期间最早心外膜激动部位的改变不如尖端扭转型室速期间明显。本研究提示，在非梗死犬模型中，尖端扭转型室速是由最早激动部位的改变而非两个或更多相互竞争的起搏点的竞争所致。
