Sra J S, Jazayeri M R, Blanck Z, Deshpande S, Dhala A A, Akhtar M
Electrophysiology Laboratory, Milwaukee Heart Institute, Sinai Samaritan Medical Center, Wisconsin.
J Am Coll Cardiol. 1994 Oct;24(4):1064-8. doi: 10.1016/0735-1097(94)90870-2.
We sought to assess the safety and efficacy of selective slow pathway ablation using radiogfrequency energy and a transcatheter technique in patients with a prolonged PR interval and atrioventricular (AV) node reentrant tachycardia.
Although both fast and slow AV node pathways can be ablated in patients with AV node reentrant tachycardia, slow pathway ablation, by obviating the risk of AV block, appears to be safer. However, the safety and efficacy of selective slow pathway ablation using transcatheter radiofrequency energy in patients with a prolonged PR interval during sinus rhythm are unclear.
The seven study patients with a prolonged PR interval (mean +/- SD 237 +/- 26 ms) comprised three women and four men with a mean age of 31 +/- 15 years. The slow pathway was targeted in all seven patients at the posterior/inferior interatrial septal aspect of the tricuspid annulus. Two patients presented with the uncommon variety of AV node reentrant tachycardia after initial fast pathway ablation; in the remaining five patients, the AV node reentrant tachycardia was of the common variety.
A single radiofrequency pulse at 30 W successfully abolished the slow pathway in both the anterograde and the retrograde direction in the two patients with uncommon AV node reentrant tachycardia. A mean of 5 +/- 3 radiofrequency pulses were required in the remaining five patients with reentrant tachycardia of the common variety. The postablation PR interval and AH interval remained unchanged. The shortest cycle length of 1:1 AV conduction was prolonged significantly (from 327 +/- 31 to 440 +/- 59 ms, p < 0.01, as was the AV node effective refractory period (from 244 +/- 35 to 344 +/- 43 ms, p < 0.01). During a mean follow-up interval of 20 +/- 6 months, no patient developed symptoms suggestive of AV node reentrant tachycardia or had evidence of second- or third-degree AV block.
These data suggest that the AV node slow pathway can be ablated in patients with AV node reentrant tachycardia who demonstrate a prolonged PR interval during sinus rhythm.
我们旨在评估采用射频能量和经导管技术对PR间期延长且患有房室结折返性心动过速的患者进行选择性慢径消融的安全性和有效性。
虽然患有房室结折返性心动过速的患者的快径和慢径均可被消融，但慢径消融因可避免房室传导阻滞的风险，似乎更为安全。然而，在窦性心律时PR间期延长的患者中，使用经导管射频能量进行选择性慢径消融的安全性和有效性尚不清楚。
7例研究患者PR间期延长（平均±标准差为237±26毫秒），包括3名女性和4名男性，平均年龄为31±15岁。所有7例患者均将慢径靶点定位于三尖瓣环后下部房间隔处。2例患者在初次快径消融后出现罕见类型的房室结折返性心动过速；其余5例患者的房室结折返性心动过速为常见类型。
在2例患有罕见房室结折返性心动过速的患者中，单次30瓦射频脉冲成功地在顺行和逆行方向阻断了慢径。其余5例患有常见类型折返性心动过速的患者平均需要5±3次射频脉冲。消融后PR间期和AH间期保持不变。1:1房室传导的最短周期长度显著延长（从327±31毫秒延长至440±59毫秒，p<0.01），房室结有效不应期也延长（从244±35毫秒延长至344±43毫秒，p<0.01）。在平均20±6个月的随访期内，无患者出现提示房室结折返性心动过速的症状，也无二度或三度房室传导阻滞的证据。
这些数据表明，对于窦性心律时PR间期延长且患有房室结折返性心动过速的患者，其房室结慢径可被消融。
