左心房高主频及连续碎裂电位电生理特点与持续性心房颤动射频消融临床疗效的关系

Effects of high dominant frequency and continuous complex fractionated atrial electrograms in the left atrium on the outcome of radiofrequency catheter ablation in patients with persistent atrial fibrillation

目的 探讨左心房（LA）高主频（HDF）及连续碎裂电位（CCFAE）的电生理特点对持续性心房颤动（AF）射频消融术疗效的影响.方法 入选宁波市第一人民医院2011年10月至2012年6月间,至少经2种抗心律失常药物治疗无效且有症状的持续性AF患者42例,在三维标测系统NavX指导下首先行环肺静脉电隔离术（PVI）,对未转复窦性心律（窦律）者继续行LA内CCFAE及HDF（最高频率位点与邻近点频率相差≥20％,DF值≥7 Hz）标测,消融终点：转为窦律且不能被诱发或消除所有CCFAE,对仍维持AF者,行直流电复律;如转为规则的房性心动过速（房速）,明确其电生理机制后进行消融终止.根据随访结果,分为PVI联合CCFAE消融窦律维持组22例（组1）与复发组16例（组2）,其中4例患者在PVI中恢复窦律,回顾性分析影响预后的因素.结果 继续CCFAE消融后15例转复窦律（10例直接转复）,5例房速经消融终止,18例接受直流电复律.随访（1.4±0.2）年,接受PVI联合CCFAE消融22例（57.9％,组1）维持窦律,两组临床特点为LA内CCFAE均值（CCFAE-mean）、CCFAE最大值（CCFAE-max）、CCFAE/LA面积比差异无统计学意义（P＞0.05）,组2平均LA内HDF值（HDF-mean）、HDF最大值（HDF-max）、HDF/LA面积比、CCFAE区域的外周（＞2 cm） HDF、CCFAE-max至HDF-max距离大于组1（P＜0.05）,组1邻近（≤2 cm） HDF的CCFAE区域数量多于组2（P＜0.05）,组1HDF-max位点频谱下降值明显高于组2（P＜0.05）.HDF/LA面积比（OR=2.19,95％CI 1.22～3.92,P＜0.05）、外周HDF的CCFAE区域（OR=0.38,95％CI0.15～0.98,P＜0.05）为射频消融复发的两个独立预测因素.结论 LA内HDF分布及CCFAE与HDF空间关系可能与持续性AF射频消融术后维持有关,提示邻近HDF的CCFAE基质改良策略有效的同时,可减少消融面积.

Objective To investigate the effect of high dominant frequency （HDF） and continuous complex fractionated atrial electrograms （ CCFAE ） in the left atrium （LA） on the efficacy of radiofrequency catheter ablation （RFCA） for persistent atrial fibrillation （PeAF）. Methods Forty-two patients with symp- tomatic persistent atrial fibrillation refractory or intolerant to antiarrhytbmic medications underwent pulmonary vein isolation （PVI） guided by NavX system （St Jude Medical）.The CCFAE and HDF （maximal frequencies surrounded by a decreasing frequency gradient I〉 20%, DF 〉I 7 Hz） mapping in the LA was performed to pa- tients whose fibrillation persisted.The procedural end point was elimination of CCFAE potentials or conversion to sinus rhythm （SR） and non-inducibility.Electrical cardioversion was performed for restoration of sinus rhythm. Whenever AF converted to an atrial tacbycardia or flutter, advanced mapping and ablation was followed.All the data were analyzed retrospectively based on the different clinical outcomes to evaluate the prognostic factors. Resuits Four patients （9.5%） converted to SR post PVI and 15 patients （39. 5%） restored SR when CCFAE ablation was accomplished.ATs in 5 patients were terminated and cardioversions were conducted in the other 18 patients.With a mean follow-up of （ 1.4±0. 2） years,SR was maintained in 22/38（57.9%） patients in groupl without any antiarrhythmic medications.No significant differences of clinical characteristic, the degree of fractiona- tion （ average value of the CCFAE-mean and CCFAE-max,proportion of the CCFAE in the LA） were detected be- tween two groups （P〉O. 05）.Patients in group 2 had higher average HDF-mean and HDF-max value, more propor- tion of HDF in LA （HDF/LA） and more HDFs in the surrounding areas of CCFAE regions （ 〉2 era） and further from HDF-max sites to CCFAE-max sites （P〈0. 05） than those in group 1.More HDFs compatible with CCFAE regions （ ≤2 cm） and more value of frequency of HDF-max reduction in the LA were observed in group 1 （P 〈0. 05）.HDF/LA ratio （ OR = 2. 19,95% CI 1.22 - 3.92, P〈0. 05） and .number of HDFs compatible with CCFAE regions （OR = 0. 38,95%CI 0. 15-0. 98 ,P〈0. 05） were the independent predictors for AF recurrence analyzed by bilogistic regression analysis. Conclusion The distribution of HDFs in LA and distance from HDFs to CCFAE might be important for AF maintenance after RFCA.The CCFAE-based substrate modification targeting surrounding region of HDF could be effective to AF termination as well as reduction of ablation areas.