持续性房颤消融术后早期复发:电复律或二次消融

目的对持续性心房颤动导管消融术后1个月内复发快速房性心律失常患者,比较早期直流电复律治疗与早期消融治疗的临床效果,为临床决策提供证据,并对持续性房颤早期复发早期消融电生理特点进行分析。方法回顾性分析2010年6月至2011年6月121例首次消融术后1个月内复发房性心动过速的持续性房颤患者,其中早期电复律69例,早期二次消融52例,平均随访(11±5)个月,分析两组的临床效果及手术组二次手术电生理特点。结果 69例早期复律患者平均随访(11±5)个月,14例维持窦性心律。52例手术患者平均随访(10±4)个月,24例维持窦性心律,早期手术组成功率较早期复律组高(46.2%比20.3%,P=0.002)。Logistic回归分析发现,左心房大小及治疗手段是房颤二次复发的独立影响因素。电生理检查发现,52例早期手术患者中,33例(63%)有肺静脉电位恢复。左上肺静脉电位恢复最多,为16支。其余肺静脉电位恢复情况分别为:左下肺静脉14支;右上肺静脉12支;右下肺静脉10支。结论持续性房颤早期复发进行早期二次消融成功率较早期电复律高。肺静脉电位恢复是持续性房颤早期复发的常见现象。     

Predictors of atrial fibrillation termination and clinical success of catheter ablation of persistent atrial fibrillation

The termination of persistent atrial fibrillation (AF) during catheter ablation has been associated in some, but not all, studies with reduced arrhythmia during clinical follow-up. We sought to determine the rate of persistent AF termination achievable with a stepwise ablation strategy, the predictors of AF termination, and the clinical outcomes associated with termination and nontermination. A total of 143 consecutive patients (age 62 ± 9 years, AF duration 5.7 ± 5.2 years) with persistent and longstanding persistent AF resistant to antiarrhythmic medication who presented in AF for catheter ablation were studied. Ablation was done with a stepwise approach, including pulmonary vein isolation, followed by complex fractionated atrial electrogram ablation and ablation of resultant atrial tachycardias. Clinical follow-up was then performed after a 2-month blanking period to assess arrhythmia recurrence, defined as AF or atrial tachycardia lasting ≥ 30 seconds. AF termination by ablation was achieved in 95 (66%) of the 143 patients. Multivariate predictors of AF termination included longer baseline AF cycle length (p <0.001) and smaller left atrial size (p = 0.002). AF termination by ablation was associated with both a lower incidence of arrhythmia recurrence after a single procedure without antiarrhythmic drugs (p = 0.01) and overall clinical success (single or multiple procedures, with or without antiarrhythmic drugs; p = 0.005). On multivariate analysis, the predictors of overall clinical success included AF termination by ablation (p = 0.001), a shorter ablation duration (p = 0.002), younger age (p = 0.02), male gender (p = 0.03), and the presence of hypertension (p = 0.03). In conclusion, among patients with persistent AF, termination of AF by ablation can be achieved in most patients and is associated with reduced recurrence of arrhythmia.     

尼非卡兰对射频消融术终未转复的持续性心房颤动的疗效观察

目的探讨尼非卡兰对渐进式导管射频消融术终仍未转复的持续心房颤动(简称房颤)的转复效果及其影响因素。方法连续入院行射频消融治疗、资料完整且符合纳入标准的持续性房颤患者共38例。对射频消融术终房颤未转复者给予单剂量静脉尼非卡兰,观察用药后30min内复律成功率。比较消融术终自动转复者(对照组)和需要应用尼非卡兰转复者(药物组)的临床情况、左房内径(LAd)、左室射血分数、手术时间、生化指标等;并比较尼非卡兰转复成功者与转复失败者的房颤持续时间、左房内径(LAd)及QTc间期等,以了解尼非卡兰转复效果及其临床影响因素。结果 38例患者,经渐进式导管消融后,15例转为窦性心律;其余23例未能转律。药物组手术时间长于对照组[(216±28)min vs(182±22)min,P<0.05],静脉注射尼非卡兰后,14例(60.9%)转复为窦性心律,从给药至房颤终止的时间为[7.3±3.3(2.5～14.5)]min;与9例尼非卡兰复律失败者相比,14例尼非卡兰复律成功者的房颤持续时间较短[(20.1±11.0)个月vs(32.8±16.2)个月,P<0.05]、LAd较小[(42.3±2.7)mm vs(45.1±3.5)mm,P<0.05]。结论对于渐进式射频消融术终未能终止的持续性房颤,静脉尼非卡兰是一种可供选择的转复方法,其效果受房颤持续时间及LAd的影响。     

伊布利特在持续性心房颤动射频消融术中转律的疗效特点

目的 评价伊布利特在持续性心房颤动(房颤)射频消融术中应用的有效性及影响因素.方法 入选接受射频消融手术的持续性房颤患者18例,男性16例,女性2例,平均年龄(56.3±14.0)岁,体质量(81.22±8.93) kg,合并原发性高血压3例、肥厚型心肌病2例.所有患者术中经环肺静脉电隔离、线性消融、碎裂电位消融后房颤未终止,或者转为心房扑动,给予伊布利特l mg、10min内静脉注射,观察开始给药后30 min内的转复率及4h内的不良反应.根据用药后是否成功转律分为转律组与非转律组.结果 (1)18例患者用药后30 min内成功转律11例,转复律为61.11％,平均转律时间为(13.80 +7.64) min,转复剂量为(0.94±0.13)mg.1例患者用药后15 min时出现窦性停搏16 s,后恢复稳定窦性心律,术后观察4h无不良反应,另1例患者用药后出现窦性心动过缓,持续约lh后恢复正常心率,期间无低血压等血流动力学改变.余16例患者术中及术后4h内无室性心动过速及低血压等不良反应.(2)使用伊布利特后30 min的AA间期(0.51±0.08)s,明显长于用药前的AA间期(0.39±0.21)s,P＜0.01;用药后30 min的QTc(0.51±0.08)s,明显长于用药前QTc(0.39±0.21)s,P＜0.01.(3)两组临床资料差异无统计学意义.转律组患者左房瘢痕区比例(5.12±3.83)％,明显小于非转律组左房瘢痕区比例(12.40±11.03)％,P＜0.01.(4)左心房内径＜40mm患者的转复率(75.00％)与内径≥40 mm患者的转复率(50.00％)差异无统计学意义(P＞0.05).结论 静脉注射伊布利特在持续性房颤射频消融术中应用疗效迅速,对消融后心房扑动转复率更高.转律的成功率与术中标测瘢痕区面积所占比例相关.     

心房颤动导管消融术后早期复发的直流电复律临床分析

目的对心房颤动(简称房颤)导管消融术后1个月内复发行直流电复律的患者的临床特征进行前瞻性研究。方法丙泊酚镇静、禁食状态下,单向波同步电复律,电极板置于心尖-胸骨旁右侧,能量依次采用300,360,360J。结果共入选23例患者,年龄58±13岁,房颤病史6.8±5.0年,左房直径41.9±9.8mm,左室射血分数0.58±0.11。复发心律失常中12例为心房扑动,10例为房颤,1例为房性心动过速。共进行27次电复律,19次(70.4%)即刻复律成功,其中15次1次放电复律成功。1例复律后出现窦性心动过缓伴交界心律,1例丙泊酚镇静时出现呼吸暂停。随访8.5±3.7个月,52.2%的患者为窦性心律。即刻复律成功组其远期成功率为64.7%,即刻复律失败的远期均不成功,两组间有显著性差异(P=0.014)。1次放电即可成功者远期成功率为69.2%,需要多次放电的患者远期成功率为20.0%,两组间有显著性差异(P=0.036)。结论直流电复律可安全有效地用于房颤导管消融术后早期复发的患者,即刻电复律成功是远期成功的预测因素,复律时需要多次放电的远期成功率低。     

Atropine-facilitated electrical cardioversion of persistent atrial fibrillation

Conventional electrical cardioversion failed to restore normal sinus rhythm (NSR) in 49 of 364 patients (13.5%) with persistent atrial fibrillation. After receiving up to 2 mg of atropine, 40 (81%) of these 49 "electrical-refractory" patients were successfully cardioverted to NSR by subsequent attempts of electrical cardioversion.     

Catheter ablation of long-lasting persistent atrial fibrillation: critical structures for termination

BACKGROUND: The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. METHODS: Sixty patients (53 +/- 9 years) undergoing catheter ablation of persistent AF (17 +/- 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. RESULTS: AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1-6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 +/- 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 +/- 14 vs 156 +/- 23 msec; P = 0.002. CONCLUSION: Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.     

Ibutilide in persistent atrial fibrillation refractory to conventional cardioversion methods

BACKGROUND: Electrical cardioversion of atrial fibrillation seems to be enhanced by pretreatment with ibutilide, but only few is known about the effects of ibutilide in atrial fibrillation which failed to convert with class III antiarrhythmic agents and electrical cardioversion. The objectives of this study were to evaluate the efficacy and safety of ibutilide administration in patients with persistent atrial fibrillation refractory to long-term therapy with class III antiarrhythmic drugs and transthoracic cardioversion. METHODS: Prospective study in 22 patients (16 men and 6 women, mean age 63+/-9 years) with structural heart disease and persistent atrial fibrillation for a mean duration of 39+/-50 (range 1-145) months. All patients had failed to convert to sinus rhythm after transthoracic cardioversion while on treatment with class III antiarrhythmic drugs (amiodarone in 82%, sotalol in 18%). One milligram of ibutilide was administered in all patients and electrical cardioversion was performed again, if necessary. RESULTS: The total conversion rate to sinus rhythm was 95% (21 of 22 patients). Two patients (9%) were successfully converted after ibutilide alone and 19 patients (86%) when transthoracic cardioversion was repeated after ibutilide. The QTc intervals increased from 451+/-28 to 491+/-49 ms (p<0.001) after ibutilide. No adverse effects occurred. The rate of freedom from atrial fibrillation after 1 month of follow-up was 64%. CONCLUSIONS: The efficacy of concomitant use of ibutilide infusion and, if necessary, repeated transthoracic cardioversion for restoration of sinus rhythm in long-term persistent atrial fibrillation and previously failed antiarrhythmic and electrical cardioversion was 95%. There were no adverse effects associated with ibutilde administration. Our results suggest that this combined strategy may be safe and successful in patients with atrial fibrillation resistant to conventional cardioversion methods and may be an alternative to internal cardioversion.     

Amiodarone after unsuccessful direct-current cardioversion of persistent atrial fibrillation

AIM: To assess the safety and efficacy of amiodarone used after unsuccessful direct current (DC) cardioversion of persistent atrial fibrillation (AF). METHODS: The study group comprised 67 patients (F/M 26/41; mean age 61.3+/-11.2 years) after unsuccessful DC cardioversion (DCC) of persistent AF (mean arrhythmia duration 212.6+/-135.2 days) in whom another attempt of DCC was intended. Repeat DC cardioversion was performed after loading with oral amiodarone, for a period necessary to achieve a cumulative dose of up to 12.0-16.0 g. Pretreatment was an outpatient procedure. After successful DC cardioversion all study subjects received a maintenance dose of amiodarone, 100-200 mg daily, aimed at preventing AF. The follow-up period was 12 months. RESULTS: Spontaneous conversion to sinus rhythm (SR) during amiodarone pretreatment was observed in 13 pts (19.2%). DCC was performed in 54 pts and SR was restored in 41 of the study pts (76%). Complications occurred in 3 pts, including 1 case of apparent hyperthyroidism and 2 cases of decreased TSH level, and required amiodarone withdrawal. After 12 months, 72.2% of pts maintained SR on low dose (179.2+/-42.1 mg/day) amiodarone. Spontaneous conversion to SR during amiodarone loading was significantly related to long-term SR maintenance after successful DC cardioversion (p<0.013; RR 2.01; 95% CI 1.34-3.03). CONCLUSION: Pretreatment with amiodarone and repeat DC cardioversion results in sinus rhythm restoration in about 80.6% of pts with persistent AF after an initial unsuccessful attempt. Direct-current cardioversion can be performed safely taking standard precautions for patients receiving amiodarone. At 12 months after successful repeated DC cardioversion, more than 72.2% of pts on low-dose amiodarone maintain SR.     

Relation of autonomic modulation to recurrence of atrial fibrillation following cardioversion

The aim of this study was to investigate the time course of changes in autonomic nervous system activity in patients with long-standing atrial fibrillation (AF) following internal electrical conversion to sinus rhythm and to look for differences between patients who do and do not relapse. Time-domain indexes of heart rate variability were calculated from 24-hour Holter recordings on the day of conversion and 1 day and 1 month afterward for 22 patients with chronic (> 3 months) AF. Ten healthy subjects served as a control group. During the day of cardioversion the mean RR interval and its circadian variation differed significantly between controls and patients. The mean values of successive RR intervals that deviated by > 50% from the prior RR interval and the root-mean-square of successive RR interval differences--indexes of vagal modulation--were initially significantly higher in patients than in controls but showed a decrease (p < 0.05) by the second day (from 12.4 +/- 7% to 8.1 +/- 5% to 7.3 +/- 5% and from 49 +/- 9 to 39 +/- 12 to 41 +/- 11 ms, respectively) to levels similar to those of the controls (7.6 +/- 5% and 40 +/- 17 ms, respectively). Only these 2 indexes contained significant prognostic information about relapse: patients who later relapsed had higher initial values than those who did not, and these values remained high during the 2 days after conversion. In conclusion, this study provides data confirming that spontaneous chronic AF in humans results in a significant increase in vagal tone that is reversed with time after restoration of sinus rhythm. Persistently higher values of vagal tone are observed in patients who relapse, and are probably a predictor for recurrence.     

持续性心房纤颤的辅助消融策略

心房纤颤（简称房颤）是一种临床上最常见的持续性心律失常,发病率高,危害大。近年来,房颤的非药物治疗取得了较快发展,其中肺静脉隔离（PVI）就是一种有效的治疗方法。这种方法对于阵发性房颤患者治愈率较高,而在持续性房颤和长时程房颤患者中疗效一般。本综述主要探讨针对持续性房颤患者的最新辅助消融策略及其机制,包括线性消融、复杂碎裂心房电位（CFAE）消融、神经节（丛）消融、主频率消融、转子消融和与房颤触发相关的其他解剖位点消融。     

Reversal of electrical remodeling after cardioversion of persistent atrial fibrillation

INTRODUCTION: In animals, atrial fibrillation results in reversible atrial electrical remodeling manifested as shortening of the atrial effective refractory period, slowing of intra-atrial conduction, and prolongation of sinus node recovery time. There is limited information on changes in these parameters after cardioversion in patients with persistent atrial fibrillation. METHODS AND RESULTS: Thirty-eight patients who had been in atrial fibrillation for 1 to 12 months underwent electrophysiologic testing 10 minutes and 1 hour after cardioversion. At 1 week, 19 patients still in sinus rhythm returned for repeat testing. Reverse remodeling of the effective refractory period was not uniform across the three atrial sites tested. At the lateral right atrium, there was a highly significant increase in the effective refractory period between 10 minutes and 1 hour after cardioversion (drive cycle length 400 ms: 204 +/- 17 ms vs 211 +/- 20 ms, drive cycle length 550 ms: 213 +/- 18 ms vs 219 +/- 23 ms, P < 0.001). The effective refractory period at the coronary sinus and distal coronary sinus did not change in the first hour but had increased by 1 week. The corrected sinus node recovery time did not change in the first hour but was shorter at 1 week (606 +/- 311 ms vs 408 +/- 160 ms, P = 0.009). P wave duration also was shorter at 1 week (135 +/- 18 ms vs 129 +/- 13 ms, P = 0.04) consistent with increasing atrial conduction velocity. CONCLUSION: The atrial effective refractory period increases, sinus node function improves, and atrial conduction velocity goes up in the first week after cardioversion of long-standing atrial fibrillation in humans. Reverse electrical remodeling of the effective refractory period occurs at different rates in different regions of the atrium.     

Initial energy for elective external cardioversion of persistent atrial fibrillation

We conducted a prospective randomized study to determine the safety and efficacy rate of 3 commonly used energy levels (100, 200, and 360 J) for elective direct-current cardioversion of persistent atrial fibrillation. When compared with 100 and 200 J, the initial success rate with 360 J was significantly higher (14%, 39%, and 95%, respectively), and patients randomized to 360 J ultimately required less total energy and a lower number of shocks.     

Defibrillation threshold of internal cardioversion prior to ablation predicts atrial fibrillation recurrence

BackgroundMany studies have reported the predictors of atrial fibrillation (AF) recurrence after persistent AF (peAF) ablation. However, the correlation between the atrial defibrillation threshold (DFT) for internal cardioversion (IC) and AF recurrence rate is unknown. Here we investigated the relationship between the DFT prior to catheter ablation for peAF and AF recurrence.HypothesisDFT prior to ablation was the predictive factor for AF recurrence after peAF ablation.MethodsFrom June 2016 to May 2019, we enrolled 82 consecutive patients (mean age, 65.0 ± 12.4 years), including 45 with peAF and 37 with long‐standing peAF, at Hamamatsu Medical Center. To assess the DFT, we performed IC with gradually increasing energy prior to radiofrequency application.ResultsForty‐nine and 33 patients showed DFT values less than or equal to 10 J (group A) and greater than 10 J or unsuccessful defibrillation (group B). During the mean follow‐up duration of 20.5 ± 13.1 months, patients in group B showed significantly higher AF recurrence rates than those in group A after the ablation procedure (p = .017). Multivariate analysis revealed that DFT was the only predictive factor for AF recurrence (odds ratio, 1.07; 95% CI, 1.00–1.13, p = .047).ConclusionsThe DFT for IC was among the strongest prognostic factors in the peAF ablation procedure.     

A strategy of rapid cardioversion minimizes the significance of early recurrent atrial tachyarrhythmias after ablation for atrial fibrillation

A Strategy of Rapid Cardioversion. Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long‐term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes. Methods: A total of 1,759 AF ablations were performed at Intermountain Medical Center or LDS Hospital. A total of 455 of those were among patients requiring repeat ablations. Patients were instructed to take their pulse daily and, if greater than 100 bpm or irregular, present the following business day fasting to the clinic for evaluation and cardioversion if AF or atrial flutter (AFL) were present. Results: Of the ablations performed, a total of 515 (29%, age: 65.6 ± 11.2 years, male: 57.9%) developed AF/AFL that required cardioverison. The majority of these arrhythmias first occurred in the initial 90 days (63.7%) postablation. During this period, 62.8% were on an antiarrhythmic drug (AAD). Only 25.1% were using an AAD at 3 months. The majority of ablations (75.6%) who experienced AF/AFL within the first 90 days after ablation were in sinus rhythm with no AAD at 1 year. Further, 48% of those with the first recurrence from 90 to 180 days were in sinus rhythm with no AAD at 1 year. Conclusions: The time at which the first recurrence of AF/AFL occurs impacts long‐term outcomes. An aggressive strategy of rapid cardioversion postablation reduces the significance of recurrent AF/AFL during the first 6 months . (J Cardiovasc Electrophysiol, Vol. 22, pp. 761‐766, July 2011)     

Tachycardia transition during ablation of persistent atrial fibrillation

Tachycardia Transition . Background: The “sequential ablation” strategy for persistent AF is aimed at progressive organization of AF until the rhythm converts to sinus rhythm or atrial tachycardia (AT). During ablation of an AT, apparently seamless transitions from one organized AT to another occur. The purpose of our study was to quantify the occurrence and the mechanism of this transition. Methods and Results: Twenty‐nine of 90 patients undergoing ablation for persistent AF had multiple AT during the procedure and constitute the study group. Thirty‐nine direct transitions from one AT to another during ablation were observed classified in four types: type I (79.4%), i.e., a direct transition of a faster to a slower tachycardia without significant intervening pause; type II (7.69%)—transition after intervening ectopy or longer pause; type III (10.26%)—A slower AT accelerated; type IV (2.56%)—alteration of activation sequence but with no change on CL. Conclusions: Transition to a second AT occurs frequently in the midst of ablation of AT in persistent AF patients. This transition occurs most commonly abruptly within the range of a single cycle length of the original AT. This is best explained by a continuation of AT that was “present” simultaneously with the pretransition tachycardia, being “entrained” (for a reentrant tachycardia) or “overdriven” for an automatic focal tachycardia. The presence of multiple tachycardia mechanisms active simultaneously would be consistent with the eclectic pathophysiology of persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 506‐512 May 2011)