Morady F, Calkins H, Langberg J J, Armstrong W F, de Buitleir M, el-Atassi R, Kalbfleisch S J
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0022.
J Am Coll Cardiol. 1993 Jan;21(1):102-9. doi: 10.1016/0735-1097(93)90723-e.
The purpose of this study was to compare direct current and radiofrequency ablation of the atrioventricular (AV) junction in a prospective randomized fashion.
Catheter ablation of the AV junction can be performed using either direct current shocks or radiofrequency energy. To date, these two techniques have never been compared prospectively or in a randomized study.
Forty patients with drug-refractory uncontrolled atrial fibrillation-flutter (38 patients) or inappropriate sinus tachycardia (2 patients) were randomly assigned to undergo direct current ablation (20 patients) using up to four shocks of 200 to 300 J or radiofrequency ablation (20 patients) using up to 15 applications of 16 to 25 W for 30 s. If complete AV block was not successfully induced, the ablation procedure was repeated using the alternate type of energy. A rate-responsive ventricular pacemaker was implanted in each patient. The intrinsic escape rhythm was evaluated 15 min, 2 days and 3, 6 and 12 months after ablation.
Persistent complete AV block was successfully induced during the first ablation session in 13 (65%) of 20 patients randomly assigned to undergo direct current ablation, compared with 19 (95%) of 20 patients randomly assigned to undergo radiofrequency ablation (p < 0.05). Each patient whose first ablation attempt failed had a successful outcome with the alternate type of energy. The overall efficacy of radiofrequency ablation (26 [96%] of 27 patients) was significantly greater than that of direct current ablation (14 [67%] of 21 patients, p < 0.01). The duration of the direct current and radiofrequency ablation sessions did not differ significantly. The mean peak plasma creatine kinase MB fraction concentration was significantly higher after direct current ablation (58 +/- 29 IU/liter) than after radiofrequency ablation (2 +/- 2 IU/liter) (p < 0.001). An escape rhythm was present 15 min after ablation in an equal proportion of patients undergoing direct current and radiofrequency ablation (78% and 85%, respectively, p = 0.6). An escape rhythm was present in all patients 3, 6 and 12 months after ablation. The mean escape rhythm cycle length 15 min after direct current ablation (2,074 +/- 677 ms) was significantly longer than that 15 min after radiofrequency ablation (1,460 +/- 294 ms) (p < 0.05); however, the mean escape rhythm cycle lengths did not differ significantly at 2 days or 3, 6 or 12 months after ablation. Immediate arrhythmic complications did not occur after either procedure. One patient died suddenly 6.5 months after direct current ablation.
Radiofrequency ablation of the AV junction is more efficacious and safer than direct current ablation and should be the preferred method for inducing complete AV block in patients who are appropriate candidates for ablation of AV conduction.
本研究旨在以前瞻性随机方式比较直流电和射频消融房室结。
房室结导管消融可使用直流电电击或射频能量进行。迄今为止，这两种技术从未在前瞻性或随机研究中进行过比较。
40例药物难治性控制不佳的心房颤动-扑动（38例）或不适当窦性心动过速（2例）患者被随机分配接受直流电消融（20例），使用高达4次200至300焦耳的电击，或射频消融（20例），使用高达15次16至25瓦、持续30秒的应用。如果未成功诱发完全性房室传导阻滞，则使用另一种能量类型重复消融程序。为每位患者植入频率应答式心室起搏器。在消融后15分钟、2天以及3、6和12个月评估固有逸搏心律。
随机分配接受直流电消融的20例患者中，13例（65%）在首次消融过程中成功诱发持续性完全性房室传导阻滞，而随机分配接受射频消融的20例患者中有19例（95%）成功诱发（p<0.05）。首次消融尝试失败的每位患者使用另一种能量类型均获得成功结果。射频消融的总体疗效（27例患者中的26例[96%]）显著高于直流电消融（21例患者中的14例[67%]，p<0.01）。直流电和射频消融疗程的持续时间无显著差异。直流电消融后血浆肌酸激酶MB同工酶峰值浓度均值（58±29国际单位/升）显著高于射频消融后（2±2国际单位/升）（p<0.001）。接受直流电和射频消融的患者中，消融后15分钟出现逸搏心律的比例相同（分别为78%和85%，p=0.6）。消融后3、6和12个月所有患者均出现逸搏心律。直流电消融后15分钟的平均逸搏心律周期长度（2074±677毫秒）显著长于射频消融后15分钟的（1460±294毫秒）（p<0.05）；然而，消融后2天或3、6或12个月时平均逸搏心律周期长度无显著差异。两种手术均未发生即刻心律失常并发症。1例患者在直流电消融后6.5个月突然死亡。
房室结射频消融比直流电消融更有效且更安全，对于适合进行房室传导消融的患者，应作为诱发完全性房室传导阻滞的首选方法。
