Raitt M H, Dolack G L, Kudenchuk P J, Poole J E, Bardy G H
Department of Medicine, University of Washington, Seattle 98195.
Circulation. 1995 Apr 1;91(7):1996-2001. doi: 10.1161/01.cir.91.7.1996.
Patients with a history of ventricular fibrillation (VF) have been shown to have a clinical profile, response to electrophysiological testing (EPS), and response to antiarrhythmic therapy that distinguishes them from patients with a history of sustained monomorphic ventricular tachycardia (MVT). Despite these differences, it is not clear whether VF in these patients is triggered by MVT or occurs de novo. The incidence of MVT and VF in such patients after their index VF event has important implications for therapeutic decisions regarding implantable defibrillator selection and programming.
The records of 111 consecutive patients who had undergone transvenous cardioverter/defibrillator (ICD) implantation for malignant ventricular arrhythmias were reviewed retrospectively. For each patient, all device tachyarrhythmia detections were examined and classified as VF, MVT, rapid polymorphic VT, or other. The number of events, time to first arrhythmia detection, and cycle length of MVTs were recorded. There were 55 patients with a history of only VF and 56 with a history that included an episode of MVT. Over 14 months of follow-up, with all patients initially off of antiarrhythmic medications, MVT was detected by only 18% of patients with a history of only VF compared with 54% of those with a history that included MVT (P = .002). Among patients who did detect MVT, those with a history of only VF had fewer episodes (7 +/- 7 versus 20 +/- 31, P = .001) and a shorter mean MVT cycle length (279 versus 314 ms, P = .03) than those with a clinical history of MVT. Abrupt onset of VF not preceded by MVT was detected in 11% of patients with VF only. In addition to a history of MVT, male sex, age < 60 years, and MVT inducible on EPS were all significantly associated with an increased likelihood of MVT detection. On multivariate analysis, the inducibility of MVT was the primary independent predictor of MVT detection but was of minimal incremental predictive value in the subgroup of patients with a history of only VF. When EPS results were not considered, arrhythmia history was the primary independent predictor of MVT detection.
Patients with a history of only VF infrequently have MVT detected by their defibrillators. When these patients do detect MVT, it is faster than that detected in patients with a clinical history of MVT before ICD surgery. A significant percentage of VF survivors detected the abrupt onset of VF not preceded by MVT, suggesting that the deterioration of rapid MVT to VF is not the only clinically important mechanism of VF induction. These findings may have important implications for the understanding of the mechanism of VF induction and for use of an implantable defibrillator.
有室颤（VF）病史的患者已被证明具有独特的临床特征、对电生理检查（EPS）的反应以及对抗心律失常治疗的反应，这使其有别于有持续性单形性室性心动过速（MVT）病史的患者。尽管存在这些差异，但尚不清楚这些患者的室颤是由室性心动过速触发还是新发的。此类患者在首次发生室颤事件后室性心动过速和室颤的发生率对于植入式除颤器的选择和程控的治疗决策具有重要意义。
回顾性分析111例因恶性室性心律失常接受经静脉心脏转复除颤器（ICD）植入的连续患者的记录。对每位患者，检查所有设备检测到的快速心律失常并分类为室颤、室性心动过速、快速多形性室性心动过速或其他。记录事件数量、首次检测到心律失常的时间以及室性心动过速的周期长度。有55例仅有室颤病史的患者和56例有室性心动过速发作史的患者。在14个月的随访期间，所有患者最初均停用抗心律失常药物，仅有18%的仅有室颤病史的患者检测到室性心动过速，而有室性心动过速发作史的患者中这一比例为54%（P = 0.002）。在确实检测到室性心动过速的患者中，仅有室颤病史的患者发作次数较少（7±7次对20±31次，P = 0.001），且平均室性心动过速周期长度短于有室性心动过速临床病史的患者（279毫秒对314毫秒，P = 0.03）。在仅有室颤的患者中，11%检测到无室性心动过速前驱的室颤突然发作。除室性心动过速发作史外，男性、年龄<60岁以及电生理检查可诱发室性心动过速均与检测到室性心动过速的可能性增加显著相关。多因素分析显示，室性心动过速的可诱发性是检测到室性心动过速的主要独立预测因素，但在仅有室颤病史的患者亚组中其增量预测价值极小。当不考虑电生理检查结果时，心律失常病史是检测到室性心动过速的主要独立预测因素。
仅有室颤病史的患者很少通过除颤器检测到室性心动过速。当这些患者确实检测到室性心动过速时，其发作速度比ICD手术前有室性心动过速临床病史的患者更快。相当比例的室颤幸存者检测到无室性心动过速前驱的室颤突然发作，这表明快速室性心动过速恶化为室颤并非室颤诱发的唯一重要临床机制。这些发现可能对理解室颤诱发机制和植入式除颤器的使用具有重要意义。
