Bergfeldt L, Rosenqvist M, Vallin H, Edhag O
Br Heart J. 1985 Mar;53(3):328-34. doi: 10.1136/hrt.53.3.328.
Syncopal attacks in patients with bifascicular block may be due to both ventricular tachyarrhythmias and intermittent atrioventricular block in addition to non-cardiac causes and lead to antiarrhythmic treatment with drugs or pacemaker or both. The acute electrophysiological effect of intravenous disopyramide 2 mg/kg body weight given over five minutes on the His-Purkinje system was assessed in 27 patients with chronic bifascicular block undergoing evaluation for permanent pacemaker treatment. The predictive value of this pharmacological stress test as regards the development of atrioventricular block during follow up was analysed. The HV interval increased (mean 43%) and the QRS duration was prolonged (mean 24%). Intrahisian or infrahisian second or third degree atrioventricular block occurred in 14 patients after disopyramide administration, requiring temporary pacing in four of them. Before the electrophysiological study 15 of the 27 patients had had at least two syncopal attacks of suspected cardiac origin but no evidence of second or third degree atrioventricular block. Second or third degree atrioventricular block was subsequently recorded in five of these 15 patients during a mean of two years follow up. The sensitivity, specificity, and predictive value of second or third degree atrioventricular block produced by disopyramide administration including subsequent atrial pacing--a positive disopyramide test--as regards later development of atrioventricular block were 80%, 90%, and 80% respectively. Intravenous administration of disopyramide to patients with bifascicular block and syncopal attacks of suspected cardiac origin may provoke atrioventricular block and asystole requiring immediate temporary pacing. Furthermore, a positive disopyramide test seems to have a significant value in predicting the later development of atrioventricular block.
双分支阻滞患者的晕厥发作可能是由于室性快速性心律失常、间歇性房室阻滞，此外还有非心脏原因，这可能导致使用药物或起搏器或两者联合进行抗心律失常治疗。对27例接受永久性起搏器治疗评估的慢性双分支阻滞患者，评估了静脉注射2mg/kg体重丙吡胺并在5分钟内给药对希氏-浦肯野系统产生的急性电生理效应。分析了这种药物应激试验对于随访期间房室阻滞发生情况的预测价值。希氏束电图的HV间期延长（平均43%），QRS时限增宽（平均24%）。14例患者在注射丙吡胺后发生希氏束内或希氏束下二度或三度房室阻滞，其中4例需要临时起搏。在电生理研究前，27例患者中有15例至少有两次疑似心脏原因的晕厥发作，但无二度或三度房室阻滞的证据。在平均两年的随访期间，这15例患者中有5例随后记录到二度或三度房室阻滞。丙吡胺给药包括随后的心房起搏（丙吡胺试验阳性）所诱发的二度或三度房室阻滞对于随后房室阻滞发生情况的敏感性、特异性和预测价值分别为80%、90%和80%。对有双分支阻滞且有疑似心脏原因晕厥发作的患者静脉注射丙吡胺可能会诱发房室阻滞和心搏停止，需要立即进行临时起搏。此外，丙吡胺试验阳性似乎在预测随后房室阻滞的发生方面具有重要价值。
