心房颤动递进式线性消融后的左心房扑动

目的旨在探讨心房颤动（房颤）递进式线性消融术中出现的房性心律失常的电生理特点及消融的结果。方法对80例房颤消融中出现规律的房性心律失常进行非接触激动顺序标测，判断电生理机制并指导消融。结果共146阵心动过速，4阵为左心房房性心动过速（房速），周长为（225±49）ms，其余142阵为左心房扑动，左心房激动时间占心动过速周长的100％，周长为（205±37）ms，均与房颤“7”字消融线上的缝隙有关。根据缝隙的位置将心房扑动的折返环分为3类：Ⅰ类（n=68），缝隙位于左心耳-左上肺静脉间的嵴部，Ⅱ类（n=50），缝隙位于左心房顶部，Ⅲ类（n=24），缝隙位于二尖瓣环峡部。其中130阵消融成功，其余16阵因消融反应欠佳后经药物或体外电转复为窦性心律。随访（16．2±6．7）个月，82．5％（66／80）的患者可维持窦性心律。结论房颤递进式线性消融术中出现的房性心律失常多为大折返机制，且与“7”字消融线上的缝隙有关，这些缝隙主要位于左心耳-左上肺静脉间的嵴部。非接触标测技术能快速准确地识别这些缝隙并指导消融。

Organized left atrial tachyarrhythmia during stepwise linear ablation for atrial fibrillation

Objective This study attempted to delineate the mechanism of organized loft atrial tachya-rrhythmia (AT) during stepwise linear ablation for atrial fibrillation (AF) using noncontact mapping. Methods Eighty patients in whom organized ATs developed or induced during stepwise linear ablation for AF were en-wiled. Left atrial (LA) activation during ATs was mapped using noncontact mapping. Radiofrequency energy was delivered to the earliest activation site or narrowest part of the re-entrant circuit of ATs. Results A total of 146 ATs were mapped. Four ATs were characterized as a focal mechanism [cycle length (225 ± 49) ms]. A macro-reentrant mechanism was confirmed in the remaining 142 ATs using noncontact mapping. LA activation time accounted for 100% of cycle length (205±37) ms. All 142 ATs used the conduction gaps in the basic fig-ure-7 lesion line. There were 3 types of circuits classified based on the gap location. Type Ⅰ (n = 68) used gaps at the ridge between left superior pulmonary vein (LSPV) and left atrial appendage (LAA). Type Ⅱ(n = 50) used gaps on the LA roof. Type Ⅲ (n = 24) passed through gaps in the mitral isthmus. Ablation at these gaps eliminated 130 ATs, but the remaining 16 ATs required cardioversion to sinus rhythm due to a poor response to ablation. Conclusion Vast majority of left ATs developed during stepwise linear ablation for AF are macro-reen-trant through conduction gaps in the basic figure-7 lesion line, especially at the ridge between LSPV and LAA. Noncontact activation mapping can identify these gaps accurately and quickly to target effective catheter ablation.