Muraoka Y, Karakawa S, Yamagata T, Matsuura H, Kajiyama G
First Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
Pacing Clin Electrophysiol. 1998 Feb;21(2):438-46. doi: 10.1111/j.1540-8159.1998.tb00069.x.
The pathogenesis of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome and the effects of elimination of accessory pathways on the appearance of atrial fibrillation are still controversial. Fifty-four patients with Wolff-Parkinson-White syndrome were classified into three groups: a No AF group (n = 24), patients without paroxysmal atrial fibrillation; an RF-AF Group (n = 12), patients with paroxysmal atrial fibrillation whose accessory pathways were eliminated using radiofrequency catheter ablation; and a Cryo-AF Group (n = 18), patients with paroxysmal atrial fibrillation whose accessory pathways were eliminated with surgical cryoablation. The electrophysiological characteristics of each group were evaluated prior to and following the elimination of their accessory pathways. As indices of atrial vulnerability, the presence of fragmented atrial activity and repetitive atrial firing zones were assessed. Inducibility of atrial fibrillation was significantly reduced following ablation of accessory pathways in the Cryo-AF group (83.3%-5.6%, P < 0.0001), while it was unchanged in the RF-AF group (83.3%-75%). In preablation studies, the effective refractory periods of the atrium in the RF-AF group and the Cryo-AF group were significantly shorter compared with the No AF group (204 +/- 18 ms, 197 +/- 16 ms vs 246 +/- 44 ms, respectively, P < 0.0001). Following ablation, the effective refractory period for patients in the Cryo-AF group was significantly prolonged compared with before ablation (197 +/- 16 ms to 232 +/- 24 ms, P < 0.0001). As a result of this prolongation of the effective refractory period of the atrium, the fragmented atrial activity and repetitive atrial response zones narrowed following ablation in the Cryo-AF group, but not in the RF-AF group. Therefore, the pathogenesis of atrial fibrillation in patients with Wolff-Parkinson-White syndrome may depend on the refractory period of the atrium rather than on the presence of accessory pathways.
预激综合征患者阵发性心房颤动的发病机制以及消除旁路对心房颤动出现的影响仍存在争议。54例预激综合征患者被分为三组：无房颤组（n = 24），即无阵发性心房颤动的患者；射频消融房颤组（n = 12），即采用射频导管消融消除旁路的阵发性心房颤动患者；冷冻消融房颤组（n = 18），即采用手术冷冻消融消除旁路的阵发性心房颤动患者。在消除旁路之前和之后评估每组的电生理特征。作为心房易损性指标，评估碎裂心房活动和重复性心房激动区域的存在情况。冷冻消融房颤组在消融旁路后心房颤动的诱发率显著降低（83.3% - 5.6%，P < 0.0001），而射频消融房颤组则无变化（83.3% - 75%）。在消融前的研究中，射频消融房颤组和冷冻消融房颤组心房的有效不应期与无房颤组相比显著缩短（分别为204 ± 18 ms、197 ± 16 ms与246 ± 44 ms相比，P < 0.0001）。消融后，冷冻消融房颤组患者的有效不应期与消融前相比显著延长（197 ± 16 ms至232 ± 24 ms，P < 0.0001）。由于心房有效不应期的这种延长，冷冻消融房颤组在消融后碎裂心房活动和重复性心房反应区域变窄，而射频消融房颤组则没有。因此，预激综合征患者心房颤动的发病机制可能取决于心房的不应期而非旁路的存在。
