伊布利特对人心脏正常传导系统及房室旁道的电生理作用

Electrophysiological effects of ibutilide on normal cardiac conduction system and accessory pathways

目的:观察新型Ⅲ类抗心律失常药物伊布利特对人心脏正常传导系统及房室旁道的电生理作用,评价其应用于电生理检查及射频消融的安全性。方法:21例经电生理检查证实为房室折返性心动过速患者,静脉注射伊布利特1mg,比较用药前、用药后即刻、15min、30min时P-A间期、A-H间期、H-V间期、QRS时限、QT间期、右室起搏下QT间期、右心房不应期、右心室不应期、房室结不应期、房室结文氏点、旁道前传及逆传不应期。结果:与用药前相比,用药后P-A间期、A-H间期、H V间期、QRS时限均无明显变化(P>0.05),QTc间期、右室起搏下QT间期、右房不应期、右室不应期、房室结文氏点均明显延长(P<0.05);与用药前相比,用药后旁道前传及逆传不应期明显延长(P<0.05),无1例出现前传或逆传功能丧失;无尖端扭转性室速及其他不良反应发生。结论:伊布利特对心脏正常传导系统的传导性无明显影响;常规剂量伊布利特能够延长旁道不应期但不阻断旁道传导功能,不影响对房室旁道的标测和消融;将其用于房室折返性心动过速患者未发生不良反应。

Objective：To observe the electrophysiological effects of ibutilide on the normal cardiac conduction system and accessory pathways（AP）of patients with accessory pathways mediated reentrant tachycardia （AVRT） and to assess the safety of ibutilide in electrophysiology study （EPS） and radiofrequency catheter ablation （RFCA）. Methods： Twenty-one patients with AVRT undergoing EPS received intravenous ibutilide （1 mg）. Electrophysiological parameters, including P-A interval, A-H interval, H-V interval, QRS complex width, QT interval, paced QT interval, right atrial effective refractory period （RA ERP）, right ventricular ERP（RV ERP）, atrioventricular node ERP （AVN ERP）, AVN block cycle length （AVN BCL）, antegrade AP ERP and retrograde AP ERP, were observed before and instantly,15 rain, and 30 min after injection of ibutilide. Results： There was no statistical difference in the P-A interval, A-H interval, H-V interval and QRS complex width before and after ibutilide injection（P〉0.05）. After injection of ibutilide, the QTc, QT intervals, the RA ERP, RV ERP, and AVN BCL were all significantly prolonged（P〈0.05）. The antegrade and retrograde ERP of AP were also increased（P〈0.05）, with no loss of antegrade and retrograde function of AP. All patients underwent successful ablation and Torsade de pointes （Tdp） and no other adverse effects were noticed. Conclusion： Ibutilide has no effect on the conductivity of normal cardiac conduction system. Routine dosage of ibutilide can prolong ERP of AP but does not block the conductivity, with no influence on eleetrophysiology study and radiofrequency catheter ablation. Ibutilide has no adverse effect on patients with AVRT.