Razavi Mehdi, Cheng Jie, Rasekh Abdi, Yang Donghui, Delapasse Scott, Ai Tomohiko, Meade Thomas, Donsky Alan, Goodman Mary J, Massumi Ali
Texas Heart Institute/St. Luke's Episcopal Hospital, Houston, Texas 77030, USA.
Pacing Clin Electrophysiol. 2006 Nov;29(11):1234-9. doi: 10.1111/j.1540-8159.2006.00528.x.
Studies indicate that success of radiofrequency (RF) ablation of atrial fibrillation (AF) may be in part due to vagal denervation. RFAof supraventricular tachycardia (SVT) has been associated with vagal denervation. The effects of slow pathway (SP) ablation on AF inducibility have not been studied.
To test the hypothesis that SP ablation renders AF less inducible.
Consecutive patients referred for SVT were studied. After atrioventricular nodal reentrant tachycardia (AVNRT) was confirmed they underwent induction of AF. After SP ablation AF induction was reattempted. Vulnerability to AF was reassessed.
Twenty-four patients were enrolled; eight were not inducible for AF in the preablative state. Mean CLof the AVNRT was 340 +/- 16 ms. The average RF ablation time was 131 +/- 42 seconds. Presence of junctional rhythm was required. Of the 16 with inducible AF two patients had AF induced during routine invasive electrophysiology study. None of these had inducible AF after SP ablation. Fourteen of 16 patients required specific AF induction. Ten of these were noninducible after SP ablation; two were inducible after SP ablation but with a more aggressive pacing protocol (P < 0.03 compared to preablation) and two had no change in AF vulnerability. Seven of the eight noninducible patients remained noninducible for AF post SP ablation. In the 12 patients who were inducible prior but noninducible after ablation the mean atrial effective refractory period (AERP) increased for both BCL at 400 and 600 ms (400/216 +/- 8 ms preablation vs 400/248 +/- 12 ms postablation, P < 0.03; 600/228 +/- 8 ms preablation vs 600/259 +/- 6 ms postablation, P < 0.04). There were no significant changes in AERP of patients who remained inducible or who were noninducible before ablation. The average ablation time for patients who became noninducible after ablation was significantly higher than those who had no change in inducibility or remained inducible but at a more aggressive pacing threshold (157 +/- 24 seconds vs 35 +/- 5 seconds; P < 0.005).
SP ablation acutely decreases vulnerability to pacing-induced AF in patients with AVNRT. This may reflect the effect of ablation on atrial vagal tone.
研究表明，射频（RF）消融心房颤动（AF）的成功可能部分归因于迷走神经去神经支配。室上性心动过速（SVT）的射频消融与迷走神经去神经支配有关。慢径路（SP）消融对AF诱发率的影响尚未得到研究。
检验SP消融使AF更不易诱发的假设。
对连续转诊来的SVT患者进行研究。在确认房室结折返性心动过速（AVNRT）后，对他们进行AF诱发。在SP消融后，再次尝试诱发AF。重新评估AF易感性。
纳入24例患者；8例在消融前不能诱发AF。AVNRT的平均周长为340±16毫秒。平均射频消融时间为131±42秒。需要有交界性心律。在16例可诱发AF的患者中，2例在常规有创电生理研究期间诱发了AF。这些患者在SP消融后均不能诱发AF。16例患者中有14例需要特异性AF诱发。其中10例在SP消融后不能诱发；2例在SP消融后可诱发，但需要更积极的起搏方案（与消融前相比，P<0.03），2例AF易感性无变化。8例不可诱发患者中的7例在SP消融后仍不可诱发AF。在12例消融前可诱发但消融后不可诱发的患者中，基础周长为400和600毫秒时的平均心房有效不应期（AERP）均增加（消融前400/216±8毫秒，消融后400/248±12毫秒，P<0.03；消融前600/228±8毫秒，消融后600/259±6毫秒，P<0.04）。仍可诱发或消融前不可诱发的患者的AERP无显著变化。消融后变为不可诱发的患者的平均消融时间显著高于那些易感性无变化或仍可诱发但起搏阈值更积极的患者（157±24秒对35±5秒；P<0.005）。
SP消融可急性降低AVNRT患者起搏诱发AF的易感性。这可能反映了消融对心房迷走神经张力的影响。
