大折返房性心动过速的电解剖标测和导管射频消融

Electroanatomic mapping and radiofrequency catheter ablation of marcro-reentry atrial tachycardia

目的应用电解剖标测系统分析3例大折返房性心动过速(房速)的电生理机制并导航消融。方法3例房速患者(男1例,女2例),平均年龄51±12岁,心动过速病史19±11年。常规电生理检查初步确定房速所在心腔,使用电解剖标测系统构建心房三维模型,完成电压和激动标测,分析心动过速的机制并确定缓慢传导区(即关键峡部),使用冷生理盐水灌注导管消融。结果3例患者临床常规检查初步排除结构性心脏病,电压标测均显示被标测心房存在疤痕区。病例1为围绕三尖瓣环顺钟向的大折返房速,关键峡部位于三尖瓣环与后侧壁的疤痕之间。病例2为围绕上腔静脉逆钟向的大折返房速,关键峡部位于右房侧壁疤痕与上腔静脉之间。病例3为左房8字形折返,关键峡部位于左房顶部的两片疤痕之间。3例患者均在关键峡部消融成功,随访9～10个月未见复发。结论电解剖标测可以揭示大折返房速的基质,阐明折返机制,并有效指导消融。

Objective To explore the mechanism of macro-reentry atrial tachycardia and to guide catheter ablation using electroanatomic mapping system in 3 patients. Methods Three patients （two females）, aged 51 ～ 12 years, with atrial tachycardia were included. The mean history of symptom was 19 ～ 11 years. Conventional electrophysiological study was performed to determine the location of atrial tachycardia before the three dimensional geometry reconstruction. After voltage and activation maps were constructed, the mechanism of tachycardia was analyzed and the slow conduction areas （critical isthmus） were verified. Radiofrequency energy was delivered using irrigated-tip catheter. Results Though there was no evidence to suggest structural heart diseases, scar areas were found in the mapped atria in all the three cases. The mechanism of atrial tachycardia was found to be counter-clockwise macro-reentry around tricuspid valve, counter-clockwise macro-reentry around superior vena cava, and figure “8” reentry in left atria in the 3 patients respectively. The respective critical isthmus was found to be between the lateral scar and tricuspid valve, the lateral scar and superior vena cava, and two scars on the left atria roof. Ablation in the critical isthmus terminated all tachycardia. There were no atrial tachycardia recurrence during a follow-up of 9 - 10 months. Conclusion The substrate and electrophysiological mechanism of macro-reentry atrial tachycardia could be identified clearly, and navigation ablation could be performed effectively under the guidence of electroanatomic mapping.