Yu J C, Lauer M R, Young C, Liem L B, Hou C, Sung R J
Cardiac Electrophysiology Laboratory, Stanford University Medical Center, CA 94305, CA.
Am Heart J. 1996 May;131(5):937-46. doi: 10.1016/s0002-8703(96)90176-3.
During radiofrequency catheter ablation of slow atrioventricular node pathway conduction in patients with atrioventricular node reentrant tachycardia, an atrioventricular junction rhythm is frequently observed. The origin and relation to ablation success of this junctional rhythm was examined in this study. By using standard intracardiac electrophysiology techniques, we studied the radiofrequency energy-induced atrioventricular junctional rhythm in 43 consecutive patients with atrioventricular node reentrant tachycardia undergoing selective ablation of slow-pathway conduction. The frequency of atrioventricular junctional activity was correlated with successful and unsuccessful attempts at ablation of slow-pathway conduction. Also, we compared the sequence of retrograde atrial activation of radiofrequency energy-induced atrioventricular junctional beats in a subgroup of 22 patients with the retrograde activation sequence observed during pacing from the right ventricular apex and the site of successful ablation of slow-pathway conduction. A total of 201 radiofrequency-energy applications was delivered in 43 patients with > or = 5 atrioventricular junctional beat(s) induced during 110 (55%) of 201 ablation attempts. Atrioventricular junctional activity was noted during 98% of successful ablations but only 43% of the unsuccessful attempts (sensitivity, 98%; specificity, 57%; negative predictive value, 99%). The mean time to appearance of atrioventricular junctional beats was 8.8 +/- 4.1 sec (mean +/- SD) after the onset of radiofrequency-energy application. In 22 (100%) of 22 patients in whom detailed atrial mapping was performed, the retrograde atrial activation sequence of the radiofrequency-induced atrioventricular junctional beats was earliest in the anterior atrial septum, identical to that seen during pacing from the right ventricular apex. Earliest retrograde atrial activation was at the posterior septum in all patients during pacing from the successful ablation site, a markedly different activation pattern compared with that seen during either radiofrequency ablation or ventricular pacing. Whereas the occurrence of atrioventricular junctional activity during radiofrequency ablation does not necessarily herald a successful ablation of slow atrioventricular node pathway conduction, its absence strongly suggests that the energy is being applied in an unsuccessful fashion. Furthermore, it appears that radiofrequency energy-induced atrioventricular junctional beats originate not from the endocardium in contact with the ablating catheter tip but instead appear to exit remotely from the anterior atrial septal region. This finding supports the existence of specialized tissues in the atrioventricular junction that preferentially transmit the effects of radiofrequency energy to an anterior exit site, possibly identical to the atrial exit site of the retrograde fast atrioventricular node conduction pathway.
在房室结折返性心动过速患者进行慢房室结通路传导的射频导管消融过程中，常观察到房室交界区心律。本研究探讨了这种交界区心律的起源及其与消融成功的关系。通过使用标准的心内电生理技术，我们研究了43例连续接受慢通路传导选择性消融的房室结折返性心动过速患者中射频能量诱发的房室交界区心律。房室交界区活动的频率与慢通路传导消融的成功和失败尝试相关。此外，我们比较了22例患者亚组中射频能量诱发的房室交界区搏动的逆行心房激动顺序与右心室尖部起搏及慢通路传导成功消融部位观察到的逆行激动顺序。43例患者共进行了201次射频能量应用，在201次消融尝试中的110次（55%）诱发了≥5次房室交界区搏动。在98%的成功消融过程中记录到房室交界区活动，但在仅43%的失败尝试中记录到（敏感性，98%；特异性，57%；阴性预测值，99%）。射频能量应用开始后，房室交界区搏动出现的平均时间为8.8±4.1秒（平均值±标准差）。在进行详细心房标测的22例患者中的22例（100%），射频诱发的房室交界区搏动的逆行心房激动顺序最早出现在前房间隔，与右心室尖部起搏时所见相同。在从成功消融部位起搏时，所有患者最早的逆行心房激动位于后间隔，与射频消融或心室起搏时所见的激动模式明显不同。虽然射频消融过程中房室交界区活动的出现不一定预示着慢房室结通路传导消融成功，但其未出现强烈提示能量应用方式不成功。此外，似乎射频能量诱发的房室交界区搏动并非起源于与消融导管尖端接触的心内膜，而是似乎从前房间隔区域远处传出。这一发现支持了房室交界区存在特殊组织，其优先将射频能量的作用传递至前出口部位，可能与逆行快房室结传导通路的心房出口部位相同。
