摘要
目的探讨心房颤动(简称房颤)患者环肺静脉左房线性消融术后二尖瓣峡部房性心动过速(简称房速)的发生机制及其消融策略。方法122例房颤患者采用EnSite-NavX和环状电极行环肺静脉左房线性消融,术后32例复发房颤或房速,8例经EnSite-NavX激动标测及拖带标测证实存在二尖瓣峡部房速,在三维导航下于左下肺静脉口部下缘至二尖瓣环之间行线性消融,对不能成功阻断二尖瓣峡部传导者予以冠状静脉窦内消融。术中同时探查双侧肺静脉电位,如传导恢复予以再次隔离。结果8例中2例呈无休止性发作,6例为阵发性,可被程序刺激诱发。房速的周长217.5±20.6ms,其中顺钟向折返5例,逆钟向折返3例。二尖瓣峡部线性消融至完全性双向传导阻滞5例,3例心内膜途径失败者经冠状静脉窦内消融,其中1例获得成功。术后随访5.5±4.3个月,6例无房颤及房速发作,1例仍有阵发性房速发作。另1例术后房速呈无休止发作,予以胺碘酮及美托洛尔控制心室率治疗。结论环肺静脉线性消融术后发生的二尖瓣峡部房速与左房线性消融治疗房颤的致心律失常作用有关,其主要的机制是消融线相关的大折返性心动过速,阻断峡部传导可以治疗此类房速。
Objective To demonstrate the mechanisms of mitral isthmus dependent atrial tachycardia （MI-AT） after circumferential pulmonary vein isolation （CPVI） for the treatment of atrial fibrillation （AF） and to discuss its ablation strategy. Methods One hundred and twenty-two consecutive patients with AF were treated with CPVI guided by EnSite- NavX and circular mapping catheter, thirty-two of which received a repeated ablation procedure because of recurrent AF or AT. MI- AT was found in eight patients who were confirmed by electrophysiologic study and EnSite-NavX mapping system. Linear lesion was performed between the ostium of left inferior pulmonary vein and the mitral annulus. If the complete bidirectional conduction block of mitral isthmus could not be achieved, further ablation would be applied within the coronary si- nus. Reisolation was necessary when reconduction between pulmonary vein and left atrium was found. Results Three-dimension mapping showed clockwise activation going around mitral ring in five patients while counterclockwise activation in three patients. The mean cycle length of MI-AT was 217.5 ± 20.6 ms. Bidirectional block of mitral isthmus was obtained in five patients after endocardial linear lesions. The left three patients which were failed by endocardial approach had coronary sinus attempt with only one success. After a mean follow up of 5.5 ±4.3 months , six patients were free of AT or AF attack, one patient still had paroxysmal AT, another patient developed incessant AT and had the medication of Amiodarone and Metoprolol to control the heart rate. Conclusions MI-AT can be developed because of the proarrhythmia effect of CPVI for the treatment of AF and also be due to macro-reentrant induced by incomplete lines. Bidirectional block of the mitral isthmus can be achieved by liner ablation between the ostium of left inferior pulmonary vein and the mitral annulus.
出处
《中国心脏起搏与心电生理杂志》
2008年第4期324-328,共5页
Chinese Journal of Cardiac Pacing and Electrophysiology
基金
卫生部课题(WKJ2004-2-004)
江苏省自然科学基金资助(BK2005218)
关键词
电生理学
心房颤动
心动过速
房性
二尖瓣峡部
导管消融
射频电流
Eleetrophysiology
Atrial fibrillation
Tachycardia, atrial
Mitral isthmus
Catheter ablation, ra diofrequency current
