Mann D E, Hartz V, Hahn E A, Reiter M J
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.
Am J Cardiol. 1997 Dec 1;80(11):1448-52. doi: 10.1016/s0002-9149(97)00729-7.
Spontaneous variability over time in the ease of induction of ventricular arrhythmias may mimic a drug effect and affect the predictive value of drug therapy guided by programmed stimulation. We assessed the effect of baseline reproducibility of arrhythmia induction on the incidence and accuracy of drug efficacy predictions in the Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial. Patients with sustained ventricular tachyarrhythmias induced twice during baseline electrophysiologic testing with the same stimulation technique, i.e., induced at the same pacing site with the same drive cycle length and number of extrastimuli, were identified from the ESVEM database. These patients with highly reproducible arrhythmia induction were compared to those with less reproducible arrhythmias. Of 473 randomized patients with reproducibility data, 313 (66%) had highly reproducible arrhythmias. In patients randomized to electrophysiologic testing, baseline arrhythmia reproducibility did not affect the incidence of drug efficacy predictions (70 of 157 [45%], drug efficacy predictions in patients with highly reproducible arrhythmias vs 34 of 79 [43%] with less reproducible arrhythmias, p = 0.890). Drug efficacy predictions obtained by electrophysiologic testing in patients with highly reproducible arrhythmias were not associated with decreases in arrhythmia recurrence (p = 0.202), all-cause mortality (p = 0.301), cardiac death (p = 0.358), or arrhythmic death (p = 0.307) compared to those with less reproducible arrhythmias. Analysis of patients with highly reproducible sustained monomorphic ventricular tachycardia led to similar results. In the ESVEM trial, most patients had highly reproducible arrhythmia induction during baseline electrophysiologic testing. Reproducibility of arrhythmia induction in the baseline state had no effect on the incidence or accuracy of drug efficacy predictions.
室性心律失常诱发的难易程度随时间的自发变化可能会模拟药物效应，并影响程序刺激引导下药物治疗的预测价值。我们在电生理研究与心电图监测（ESVEM）试验中评估了心律失常诱发的基线可重复性对药物疗效预测的发生率和准确性的影响。通过ESVEM数据库确定了在基线电生理测试期间使用相同刺激技术两次诱发持续性室性快速性心律失常的患者，即在相同的起搏部位以相同的驱动周期长度和额外刺激次数进行诱发。将这些心律失常诱发高度可重复的患者与心律失常诱发可重复性较差的患者进行比较。在473例有可重复性数据的随机分组患者中，313例（66%）心律失常诱发高度可重复。在随机接受电生理测试的患者中，基线心律失常可重复性不影响药物疗效预测的发生率（157例中有70例[45%]，心律失常诱发高度可重复的患者药物疗效预测与79例中有34例[43%]心律失常诱发可重复性较差的患者相比，p = 0.890）。与心律失常诱发可重复性较差的患者相比，通过电生理测试在心律失常诱发高度可重复的患者中获得的药物疗效预测与心律失常复发减少（p = 0.202）、全因死亡率（p = 0.301）、心源性死亡（p = 0.358）或心律失常性死亡（p = 0.307）无关。对心律失常诱发高度可重复的持续性单形性室性心动过速患者的分析得出了类似的结果。在ESVEM试验中，大多数患者在基线电生理测试期间心律失常诱发高度可重复。基线状态下心律失常诱发的可重复性对药物疗效预测的发生率或准确性没有影响。
