MacLean W A, Plumb V J, Waldo A L
Pacing Clin Electrophysiol. 1981 Jul;4(4):358-66. doi: 10.1111/j.1540-8159.1981.tb03713.x.
The effects on spontaneously occurring ventricular tachycardia of rapidly pacing the right ventricle at rates faster than the rate of the ventricular tachycardia were studied during 10 episodes in seven patients. In three episodes, ventricular pacing interrupted the ventricular tachycardia at the initial pacing rate (111%, 114%, and 119% of the ventricular tachycardia rate, respectively). In seven episodes, the initial pacing rate failed to interrupt the ventricular tachycardia. In six of those seven episodes, the ventricular tachycardia was transiently entrained to the faster pacing rates. In one of those seven episodes, transient entrainment of the ventricular tachycardia could not be distinguished from over-drive suppression. In all seven episodes, the tachycardia was later interrupted by pacing at more rapid rates. The successful pacing rate ranged from 111-141% (mean 125%) of the spontaneous ventricular tachycardia rate. It is concluded that when utilizing rapid ventricular pacing to interrupt ventricular tachycardia, a critical pacing rate may be required before interruption is achieved. Pacing at rates slower than the critical rate but faster than the spontaneous ventricular tachycardia rate may only transiently entrain the ventricular tachycardia to the pacing rate without interrupting it. During the period of transient entrainment, fusion QRS complexes are likely to be present.
在7例患者的10次发作期间，研究了以高于室性心动过速速率的频率快速起搏右心室对自发发生的室性心动过速的影响。在3次发作中，心室起搏以初始起搏速率（分别为室性心动过速速率的111%、114%和119%）中断了室性心动过速。在7次发作中，初始起搏速率未能中断室性心动过速。在这7次发作中的6次，室性心动过速被短暂拖带至更快的起搏速率。在这7次发作中的1次，室性心动过速的短暂拖带与超速抑制无法区分。在所有7次发作中，心动过速后来通过更快速率的起搏而中断。成功的起搏速率范围为自发室性心动过速速率的111%-141%（平均125%）。结论是，当利用快速心室起搏中断室性心动过速时，在实现中断之前可能需要一个临界起搏速率。以低于临界速率但高于自发室性心动过速速率的速率起搏可能只会使室性心动过速短暂拖带至起搏速率而不会中断它。在短暂拖带期间，可能会出现融合QRS波群。
