Houltz B, Darpö B, Edvardsson N, Blomström P, Brachmann J, Crijns H J, Jensen S M, Svernhage E, Vallin H, Swedberg K
Department of Medicine, Sahlgrenska University Hospital, Ostra, Göteborg, Sweden.
Pacing Clin Electrophysiol. 1998 May;21(5):1044-57. doi: 10.1111/j.1540-8159.1998.tb00150.x.
The aim of this study was to identify predictors of torsades de pointes (TdP) in patients with atrial fibrillation (AF) or flutter exposed to the Class III antiarrhythmic drug almokalant. TdP can be caused by drugs that prolong myocardial repolarization. One hundred patients received almokalant infusion during AF (infusion 1) and 62 of the patients during sinus rhythm (SR) on the following day (infusion 2). Thirty-two patients converted to SR. Six patients developed TdP. During AF, T wave alternans was more common prior to infusion (baseline) in patients developing TdP (50% vs 4%, P < 0.01). After 30 minutes of infusion 1, the TdP patients exhibited a longer QT interval (493 +/- 114 vs 443 +/- 54 ms [mean +/- SD], P < 0.01), a larger precordial QT dispersion (50 +/- 74 vs 27 +/- 26 ms, P < 0.05), and a lower T wave amplitude (0.12 +/- 0.21 vs 0.24 +/- 0.16 mV, P < 0.01). After 30 minutes of infusion 2, they exhibited a longer QT interval (672 +/- 26 vs 489 +/- 74 ms, P < 0.001), a larger QT dispersion in precordial (82 +/- 7 vs 54 +/- 52 ms, P < 0.01) and extremity leads (163 +/- 0 vs 40 +/- 34 ms, P < 0.001), and T wave alternans was more common (100% vs 0%, P < 0.001). Risk factors for development of TdP were at baseline: female gender, ventricular extrasystoles, and treatment with diuretics; and, after 30 minutes of infusion: sequential bilateral bundle branch block, ventricular extrasystoles in bigeminy, and a biphasic T wave. Patients developing TdP exhibited early during almokalant infusion a pronounced QT prolongation, increased QT dispersion, and marked morphological T wave changes.
本研究的目的是确定暴露于Ⅲ类抗心律失常药物阿尔莫卡兰的心房颤动（AF）或心房扑动患者发生尖端扭转型室性心动过速（TdP）的预测因素。TdP可由延长心肌复极的药物引起。100例患者在房颤期间接受阿尔莫卡兰输注（输注1），次日62例患者在窦性心律（SR）期间接受输注（输注2）。32例患者转为窦性心律。6例患者发生TdP。在房颤期间，发生TdP的患者在输注前（基线）T波交替更常见（50%对4%，P<0.01）。输注1 30分钟后，TdP患者的QT间期更长（493±114对443±54毫秒[平均值±标准差]，P<0.01），胸前导联QT离散度更大（50±74对27±26毫秒，P<0.05），T波振幅更低（0.12±0.21对0.24±0.16毫伏，P<0.01）。输注2 30分钟后，他们的QT间期更长（672±26对489±74毫秒，P<0.001），胸前导联（82±7对54±52毫秒，P<0.01）和肢体导联（163±0对40±34毫秒，P<0.001）的QT离散度更大，T波交替更常见（100%对0%，P<0.001）。TdP发生的危险因素在基线时为：女性、室性期前收缩和利尿剂治疗；输注30分钟后为：序贯性双侧束支传导阻滞、二联律室性期前收缩和双向T波。发生TdP的患者在阿尔莫卡兰输注早期表现出明显的QT延长、QT离散度增加和明显的T波形态改变。
