Chalak W, Taha A, Araoya M, Rifaat M
Middle East Hospital, Beirut, Lebanon.
J Med Liban. 1993;41(2):62-8; discussion 68-9.
Eighteen patients with long QT interval and recurrent ventricular tachycardia, torsade de pointe, were studied. Fourteen patients had an underlying heart disease. The factors involved in the appearance of this arrhythmia were: antiarrhythmic drugs (55.5%), complete heart block (33.5%), Romano-Ward syndrome (5.5%) and hypokalemic periodic paralysis (5.5%). In drug-induced torsade de pointe the QT interval was moderately prolonged. Seven patients (70%) had hypokalemia and 5 patients were bradycardic (50%). In patients with heart block-induced torsade de pointe, the QT interval was markedly prolonged. The ventricular rate was markedly slow (38 beat/min +/- 6 SD), and hypokalemia was less obvious (33.3%). In all cases there were ventricular extrasystoles with bigeminy, couplets or polymorphism on the basic ECG. Long-short sequence initiating the torsade de pointe was observed in 83 out of the 92 episodes. The withdrawal of the offensive drug or the correction of a treatable cause was sufficient to prevent torsade de pointe while the use of isoproterenol was effective in 7 patients who received this drug alone or prior to the ventricular pacing which was successfully used in 9 patients. Lidocaine was ineffective or had deleterious effects in 15 patients where electrical cardioversion required repeated use with an average of 5 times/patient.
对18例长QT间期并反复发作室性心动过速（尖端扭转型室速）的患者进行了研究。14例患者有潜在的心脏病。该心律失常出现所涉及的因素有：抗心律失常药物（55.5%）、完全性心脏传导阻滞（33.5%）、 Romano-Ward综合征（5.5%）和低钾性周期性麻痹（5.5%）。在药物诱发的尖端扭转型室速中，QT间期呈中度延长。7例患者（70%）有低钾血症，5例患者有心动过缓（50%）。在心脏传导阻滞诱发的尖端扭转型室速患者中，QT间期明显延长。心室率明显缓慢（38次/分钟±6标准差），低钾血症不太明显（33.3%）。在所有病例中，基础心电图上均有室性早搏，呈二联律、成对或多形性。在92次发作中的83次观察到长-短序列引发尖端扭转型室速。停用致病药物或纠正可治疗的病因足以预防尖端扭转型室速，而使用异丙肾上腺素对7例单独使用该药或在心室起搏前使用该药的患者有效，心室起搏在9例患者中成功应用。利多卡因对15例患者无效或有有害作用，这些患者需要反复进行电复律，平均每人5次。
