阵发性心房颤动大静脉电隔离后肌袖内自发电活动的特点

目的　总结阵发性心房颤动 (房颤 )患者大静脉 (肺静脉和 /或上腔静脉 )电隔离治疗后肌袖内自发电活动的特点 ,探讨其临床意义。方法　顽固性特发性房颤患者 ,在环状标测电极导管指导下行心内电生理标测以及肺静脉和 /或上腔静脉肌袖的射频导管消融电隔离治疗 ,电隔离后继续留置环状标测导管 10～ 2 0min ,观察自发电位发生情况。结果　电隔离前心内标测显示 32例患者的 36根大静脉肌袖有自发电活动。以心房 大静脉传入阻滞为终点行大静脉口部消融后 ,16根 (4 4 % )记录到大静脉内自发电活动 ,其中 2根呈偶发的单一电活动 ,11根呈平均频率 (38± 12 )次 /min的缓慢节律 ,3根呈偶发的由 3～ 6个电位组成的短阵快速节律。 15根示大静脉内电活动与心房完全分离 (93 8% ) ,1根左上肺静脉存在大静脉 心房单向传导。结论　射频导管消融电隔离大静脉后 ,出现心房 大静脉传入阻滞时多同时伴有大静脉 心房传出阻断 ,心房 大静脉传入阻滞后大静脉内的电活动频率明显变慢、减少或消失 ,说明窦性心律时的心房 大静脉传导是引起大静脉内电活动不稳定的重要原因 ,射频导管消融技术即使只阻断心房 大静脉单向传导也可通过稳定大静脉内电活动而减少或控制房颤的发作。

Characteristics and clinical significance of spontaneous electrical activity in the big veins in patients with paroxysmal atrial fibrillation after electrical isolation

Objective The characteristics of spontaneous electrical discharges in the electrically isolated myocardial sleeves of pulmonary veins(PV)and superior vene cava(SVC)were studied in patients with paroxysmal atrial fibrillation. Methods Thirty-two patients with spontaneous PV and SVC electrical activities documented on intracardial electrophysiologic study(EPS)were included.After the electrical isolation by radiofrequency catheter ablation,lasso mapping catheter were remained in the big veins for 20 minutes to monitor the spontaneous potentials in each isolated PV or SVC.Results Spontaneous electrical discharges were recorded in 36 veins,including 31 PVs and 5 SVCs.After the segmental ablation at the veno-atiral junction with the end-point of disappearance of PV and SVC potentials during sinus rhythm and atrial pacing,16 veins(44%)demonstrated a spontaneous electrical activities,among which 11 veins showed a rhythm with an average rate of 35 bpm.Fifty of Sixty veins(93.8%)showed complete dissociation with the atrial potential,and only one left superior pulmonary vein had intermittent veno-atrium conduction which was blocked by another session of delivery of radiofrequency current.Conclusion The elimination of PV and SVC potentials during sinus rhythm or atrial pacing by segmental ablation at the ostium of the big veins generally indicates the occurrence of bi-directional conduction block between big veins and the atrium,which suggested the evaluation of exit block by pulmonary vein pacing is usually not required.The electrical discharges almost always resolved or significantly decreased upon big vein isolation,which suggests that the normal atrial electrical activity conducting into the vein played an important role to the occurrence of electrical firing in the veins.