Moroe K, Saku K, Tashiro N, Hiroki T, Arakawa K
Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
Clin Cardiol. 1988 Jan;11(1):9-13. doi: 10.1002/clc.4960110111.
In order to elucidate the trigger factor of the production of torsades de pointes (TdP), electrophysiological study was conducted in 15 patients with atrioventricular (AV) block; 6 with TdP (TdP group) and 9 without TdP (control group). In the TdP group, all had an episode of syncope and frequent ventricular premature beats (VPBs) on routine ECG, while four (44%) had syncope and three (33%) had VPBs in the control group. Aging, QRS width, ventricular cycle length, QT interval, and block site from His bundle electrogram were similar in both groups, however the QTc interval was significantly (p less than 0.01) longer in the TdP group than in the control group (580 +/- 112 vs. 459 +/- 37, respectively). Furthermore, four patients (67%) in the TdP group showed advanced AV block in which a slow ventricular rate and an irregular rhythm were characteristic, whereas only one control (11%) showed advanced AV block and all other control patients (89%) had complete AV block. These data indicate that patients with advanced atrioventricular block associated with prolonged QTc interval and frequent ventricular premature beats might induce torsades de pointes.
为了阐明尖端扭转型室性心动过速（TdP）产生的触发因素，对15例房室（AV）阻滞患者进行了电生理研究；其中6例发生TdP（TdP组），9例未发生TdP（对照组）。在TdP组中，所有患者在常规心电图上均有晕厥发作和频发室性早搏（VPB），而对照组中有4例（44%）有晕厥，3例（33%）有VPB。两组患者的年龄、QRS波宽度、心室周期长度、QT间期以及希氏束电图的阻滞部位相似，然而TdP组的QTc间期显著（p<0.01）长于对照组（分别为580±112和459±37）。此外，TdP组中有4例患者（67%）表现为高度房室阻滞，其特征为心室率缓慢且节律不规则，而对照组中只有1例（11%）表现为高度房室阻滞，其他所有对照患者（89%）均为完全性房室阻滞。这些数据表明，伴有QTc间期延长和频发室性早搏的高度房室阻滞患者可能诱发尖端扭转型室性心动过速。
