Shimizu H, Ohnishi Y, Inoue T, Yokoyama M
Department of Internal Medicine, Kobe University School of Medicine, Kobe, Japan.
J Electrocardiol. 2001 Apr;34(2):119-25. doi: 10.1054/jelc.2001.23361.
The present study evaluates the repolarization abnormalities in patients with monomorphic sustained ventricular tachycardia (MVT) and polymorphic ventricular tachycardia/ventricular fibrillation (PMVT/VF) by measuring QT and JT dispersion on the surface electrocardiogram (ECG). QT dispersion is a predictor of ventricular arrhythmias in several clinical settings. However, the value of QT and JT dispersion in identifying patients at risk for PMVT/VF is controversial. Maximum QT (JT) interval duration and QT (JT) dispersion were compared between 20 healthy individuals, 12 patients with inducible MVT during programmed electrical stimulation and seven patients with PMVT/VF recorded during 24-hour ambulatory ECG or induced by programmed electrical stimulation. QT dispersion was 40 +/- 9 ms in the control group, 63 +/- 21 ms in the MVT group, and 79 +/- 31 ms in the PMVT/VF group. QT dispersion in both the MVT and PMVT/VF groups were significantly greater than in the control group (P <.001 and P <.0001, respectively); however, there was no significant difference between the MVT and PMVT/VF groups. JT dispersion was 41 +/- 14 ms in the control group, 69 +/- 14 ms in the MVT group and 103 +/- 37 ms in the PMVT/VF group. JT dispersion differed significantly between the study groups and was significantly increased in PMVT/VF group than in the control group or MVT groups (P <.0001 vs. the control group, P <.005 vs. the MVT group). Patients with PMVT/VF have a greater dispersion of ventricular repolarization time. Repolarization abnormalities are important for ventricular arrhythmogenesis and detectable on the surface ECG.
本研究通过测量体表心电图（ECG）上的QT和JT离散度，评估单形性持续性室性心动过速（MVT）和多形性室性心动过速/心室颤动（PMVT/VF）患者的复极异常。QT离散度是多种临床情况下室性心律失常的预测指标。然而，QT和JT离散度在识别PMVT/VF风险患者中的价值存在争议。比较了20名健康个体、12名在程序电刺激期间可诱发MVT的患者和7名在24小时动态心电图记录期间或由程序电刺激诱发的PMVT/VF患者的最大QT（JT）间期时长和QT（JT）离散度。对照组的QT离散度为40±9毫秒，MVT组为63±21毫秒，PMVT/VF组为79±31毫秒。MVT组和PMVT/VF组的QT离散度均显著大于对照组（分别为P<.001和P<.0001）；然而，MVT组和PMVT/VF组之间无显著差异。对照组的JT离散度为41±14毫秒，MVT组为69±14毫秒，PMVT/VF组为103±37毫秒。研究组之间的JT离散度存在显著差异，PMVT/VF组的JT离散度显著高于对照组或MVT组（与对照组相比P<.0001，与MVT组相比P<.005）。PMVT/VF患者的心室复极时间离散度更大。复极异常对室性心律失常的发生很重要，且可在体表心电图上检测到。
