三磷酸腺苷对室房传导的电生理作用

Electrophysiologic effects of ATP on ventriculoatrial conduction in patients with atrioventricular junctional reentrant tachycardia or atrioventricular reciprocating tachycardia

目的 探讨三磷酸腺苷 (adenosine triphosphate,ATP)对房室结双径路参与的房室交界区折返性心动过速和旁路参与的房室折返性心动过速患者的室房传导的电生理作用。 方法 39例房室交界区折返性心动过速和 6 7例房室折返性心动过速患者在右心室起搏 (频率 140次 / m in)时 ,经股静脉快速注射 ATP 2 0 mg,连续记录体表心电图和心内电图 ,观察室房传导变化。 结果 房室交界区折返性心动过速组 33例 (84.6 % )在注射 ATP后出现室房阻滞 ,其余 6例无变化。6 7例房室旁路患者在消融前 ,6 1例 (91% )室房传导无变化 ,另 6例出现室房阻滞 ,其中 2例具递减性传导 ;而在消融后 2 4例右心室起搏频率超过 16 0次 / m in,仍为 1∶ 1逆传 ,注射 ATP后 2 3例出现室房阻滞 ,仅 1例不受影响。 结论 ATP对房室结及旁路的电生理作用不同 ,注射 ATP后出现室房阻滞对鉴别经房室结或旁路逆传有一定价值 ,是旁路消融成功的一个判别指标 。

Objective The electrophysiologic effects of ATP on ventriculoatrial (VA) conduction in patients with atrioventricular junctional reentrant tachycardia(AVJRT) or atrioventricular reciprocating tachycardia(AVRT)were studied. Method During right ventricular patcing at a constant rate of 140 ppm,a bolus of 20 mg ATP was injected via the right femoral vein in 106 patients with praxysmal AVJRT(39 cases)and AVRT(67 cases),continuous surface and intracardiac electrograms were recorded and ventriculoatrial conduction was assessed. Result After injecton of ATP,transient VA block was observed in 33 patients with AVJRT,no changes of VA conduction occurred in the remaining 6 patients.Prior to ablation,ATP had no effects on conduction in 61 patients with AVRT,but transient VA block was observed in the remaining 6 patients.After ablation of accessory tract,there was 1∶1 VA conduction in 24 patients during RV pacing at 160 ppm,but VA block was observed after injection of ATP in 23 of them. Conclusion The effects of ATP on VA conduction differ in patients with AVJRT and AVRT.Transient VA block following an ATP bolus cannot be used as the sole end point of succesful ablation of atrioventricular accessory tract nor a reliable criterion to distinguish VA conduction over the atrioventricular node from that over the atrioventricular accessory tract.