High-density activation mapping of fractionated electrograms in the atria of patients with paroxysmal atrial fibrillation

BACKGROUND: Areas of complex fractionated atrial electrograms (CFAEs) have been implicated in the atrial substrate of atrial fibrillation (AF). The mechanisms underlying CFAE in humans are not well investigated. OBJECTIVES: The purpose of this study was to investigate the regional activation pattern associated with CFAE using a high-density contact mapping catheter. METHODS: Twenty patients with paroxysmal AF were mapped using a high-density multielectrode catheter. CFAE were mapped at 10 different sites (left atrium [LA]: inferior, posterior, roof, septum, anterior, lateral; right atrium [RA]: anterior, lateral, posterior, septum). Local atrial fibrillation cycle length (AFCL) was measured immediately before and after the occurrence of CFAE, and the longest electrogram duration (CFAEmax) was assessed. RESULTS: Longer electrogram durations were recorded in the LA compared with the RA (CFAEmax 118 +/- 21 ms vs 104 +/- 23 ms, P = .001). AFCL significantly shortened before the occurrence of CFAEmax compared with baseline (LA: 174 +/- 32 ms vs 186 +/- 32 ms, P = .0001; RA: 177 +/- 31 ms vs 188 +/- 31 ms, P = .0001) and returned to baseline afterwards. AFCL shortened by >or=10 ms in 91% of mapped sites. Two different local activation patterns were associated with occurrence of CFAEmax: a nearly simultaneous activation in all spines in 84% indicating passive activation, and a nonsimultaneous activation sequence suggesting local complex activation or reentry. CONCLUSION: Fractionated atrial electrograms during AF demonstrate dynamic changes that are dependent on regional AFCL. Shortening of AFCL precedes the development of CFAE; thus, cycle length is a major determinant of fractionation during AF. High-density mapping in AF may help to differentiate passive activation of CFAE from CFAE associated with an active component of the AF process.     

Impact of pre-existent areas of complex fractionated atrial electrograms on outcome after pulmonary vein isolation

Background Atrial fibrillation (AF) drivers outside pulmonary veins (PV) may account for failure after PV isolation. The aim of this study was to characterize pre-existent areas of complex fractionated atrial electrograms (CFAEs) recorded in right atrium (RA) and in coronary sinus (CS) during catheter-based PV isolation and to assess their relation to outcome. Methods and results With a tricuspid annulus and CS mapping, CFAEs were retrospectively identified in consecutive patients who underwent PV isolation. Of 224 patients, 161 were found to have CFAEs (81%). No clinical variable was found to be predictive of CFAEs presence. By Kaplan–Meier analysis, following a median follow-up of 23.7 months after a single ablation procedure, 62.8% of patients in the CFAEs(+) group and 85.4% of those in the CFAEs(−) group were free from recurrent atrial tachyarrhythmias (p = 0.013). Multivariable Cox regression analysis showed that CFAEs evidence was an independent predictor of recurrence (p = 0.007). Conclusions Pre-existent CFAEs, that can be easily identified in RA and CS during PV isolation, are a powerful independent predictor for AF recurrence. This finding may be helpful for refining AF ablation strategies.     

Prospective study of atrial fibrillation termination during ablation guided by automated detection of fractionated electrograms

Introduction: Complex fractionated atrial electrograms (CFAE) may identify critical sites for perpetuation of atrial fibrillation (AF) and provide useful targets for ablation. Current assessment of CFAE is subjective; automated detection algorithms may improve reproducibility, but their utility in guiding ablation has not been tested.
Methods and Results: In 67 patients presenting for initial AF ablation (42 paroxysmal, 25 persistent), LA and CS mapping were performed during induced or spontaneous AF. CFAE were identified by an online automated computer algorithm and displayed on electroanatomical maps. A mean of 28 ± 18 sites/patient were identified (20 ± 13% of mapped sites), and were more frequent during persistent AF. CFAE occurred most commonly within the CS, on the atrial septum, and around the pulmonary veins. Ablation initially targeting CFAE terminated AF in 88% of paroxysmal AF, but only 20% of persistent AF (P < 0.001). Subsequently, additional ablation was performed in all patients (PV isolation for paroxysmal AF, PV isolation + mitral and roof lines for persistent AF). Minimum follow-up was 1 year. One-year freedom from recurrent atrial arrhythmias without antiarrhythmic drug therapy after a single procedure was 90% for paroxysmal AF, and 68% for persistent AF.
Conclusions: Ablation guided by automated detection of CFAE proved feasible, and was associated with a high AF termination rate in paroxysmal, but not persistent AF. As an adjunct to conventional techniques, it was associated with excellent long-term single procedure outcomes in both groups. Criteria for identifying optimal CFAE sites for ablation, and selection of patients most likely to benefit, require additional study.     

Consistency of complex fractionated atrial electrograms during atrial fibrillation

BACKGROUND: Temporal variation in complex fractionated atrial electrograms (CFAEs) exists during atrial fibrillation (AF). OBJECTIVE: This study sought to quantify the variation in CFAEs using a fractionation interval (FI) algorithm and to define the shortest optimal recording duration required to consistently characterize the magnitude of the fractionation. METHODS: Twenty-seven patients undergoing AF mapping in the left atrium were studied. The FI and frequency analysis were performed at each mapped site for recording durations of 1 to 8 seconds. The magnitude of the fractionation was quantified by the FI algorithm, which calculated the mean interval between multiple, discrete deflections during AF. The results from each duration were statistically compared with the maximal-duration recording, as a standard. The FI values were compared with the dominant frequency values obtained from the associated frequency spectra. RESULTS: The FIs obtained from recording durations between 5 and 8 seconds had a smaller variation in the FI (P < .05) and, for those sites with a FI < 50 ms, the fractionation was typically continuous. The fast-Fourier Transform spectra obtained from the CFAE sites with recording durations of >5 seconds harbored higher dominant frequency values than those with shorter recording durations (8.1 +/- 2.5 Hz vs. 6.8 +/- 0.98 Hz, P < .05). The CFAE sites with continuous fractionation were located within the pulmonary veins and their ostia in 77% of patients with paroxysmal AF, and in only 29% of patients with nonparoxysmal AF (P < .05). CONCLUSION: The assessment of fractionated electrograms requires a recording duration of > or =5 seconds at each site to obtain a consistent fractionation. Sites with the shortest FIs consistently identified sites with the fastest electrogram activity throughout the entire left atrium and pulmonary veins.     

老年对慢性心房颤动患者左房复杂碎裂电位的影响

目的 评价老年对非瓣膜病心房颤动（简称房颤）患者左房复杂碎裂电位（CFAEs）的影响。方法 前瞻性入选116例行导管消融的慢性房颤患者。 以60岁为界,分为老年组（n=48）与非老年组（n=68）。 在CARTO系统指导下记录局部稳定的心内膜电图。 应用CARTO系统内置的CFAEs分析软件进行分析。 以间期置信水平（ICL）来评估CFAEs的特点。 CFAEs指数定义为 ICL≥7 区域的面积与左房表面积的比值。 将左房分为前壁、后壁、顶部、下壁、外侧壁、间隔六个部分,评价CFAEs在左房不同位置的分布特征。 结果 老年组男性患者比例显著低于非老年组,合并高血压、脑卒中的比例显著高于非老年组（P均〈0. 05）。 老年组最大ICL显著大于非老年组[（16.7±2.0） vs （15.7±2.2）,P=0. 014）],老年组CFAEs指数显著高于非老年组[（60. 4%±22.9% ） vs （48. 6%±22. 3% ）,P=0. 007）]。 老年组左房前壁、间隔的CFAEs的分布比例显著大于非老年组。 年龄与CFAEs指数呈正相关（r=0. 244, P=0. 008）。 结论 老年慢性房颤具有广泛的 CFAEs。     

Mechanism of recurrence after radiofrequency catheter ablation of atrial fibrillation guided by complex fractionated atrial electrograms

Background A better understanding of the mechanisms of recurrent atrial fibrillation (AF) after radiofrequency ablation of complex, fractionated atrial electrograms (CFAEs) may be helpful for refining AF ablation strategies. Methods and results Electrogram-guided ablation (EGA) was repeated in 30 consecutive patients (mean age = 59 ± 8 years) for recurrent paroxysmal AF, 10 ± 4 months after the first ablation. During the first procedure, CFAEs were targeted without isolating all pulmonary veins (PVs). During repeat ablation, all PVs and the superior vena cava (SVC) were mapped with a circular catheter and the left atrium was mapped for CFAEs. EGA was performed until AF was rendered noninducible or all identified CFAEs were eliminated. During repeat ablation, ≥1 PV tachycardia was found in 83 PVs in 29 of the 30 patients (97%). Among these 83 PVs, 63 (76%) had not been completely isolated previously. During repeat ablation, drivers originating in a PV or PV antrum were identified only after infusion of isoproterenol (20 μg/min) in 12 patients (40%). At 9 ± 4 months of follow-up after the repeat ablation procedure, 21 of the 30 patients (70%) were free from recurrent AF and flutter without antiarrhythmic drugs. Conclusions Recurrence of AF after EGA is usually due to PV tachycardias. Therefore, it may be preferable to systematically map and isolate all PVs during the first procedure. High-dose isoproterenol may be helpful to identify AF drivers.     

Electrophysiological characteristics of complex fractionated electrograms and high frequency activity in atrial fibrillation

Background

It is unclear whether atrial substrate with complex fractionated electrograms (CFAEs) is related to arrhythmogenesis. This study aimed to investigate the electrophysiology in CFAE and high dominant frequency (DF) areas.

Methods and results

Atrial fibrillation (AF) was induced by rapid atrial pacing in heart failure (HF) rabbits (4 weeks after coronary artery ligation). Real-time substrate mapping, multielectrode array, and monophasic action potential recordings were used to study areas of CFAE and DF. Conventional microelectrode and western blot were used to record the action potentials (APs) and protein expression in isolated tissue preparations. CFAE site with high DF had the most depolarized resting membrane potential, highest incidence of early and delayed afterdepolarizations, and steepest maxima slope of 90% of AP duration (APD₉₀) restitution curve (RC) compared to CFAE site with low DF or non-CFAE sites. CFAE site with high DF exhibited the slowest conduction velocity and shortest wavelength than the other areas. Upregulation of the Na⁺–Ca^2 + exchanger (NCX), apamin-sensitive small-conductance Ca^2 +-activated K⁺ channel type 2 (SK2) and sarcoplasmic reticulum Ca^2 +-ATPase, and downregulation of the Kir2.1 were found at CFAE site with high DF compared to that observed in the 3 other areas. Inhibition of the NCX and SK channels prolonged the APD₉₀, flattened the maximum slope of RC, and suppressed AF.

Conclusions

CFAE site with high DF had an arrhythmogenic property differing significantly from the other areas of LA in an HF rabbit model, which may contribute to the genesis of AF.     

Automatic 3D mapping of complex fractionated atrial electrograms (CFAE) in patients with paroxysmal and persistent atrial fibrillation

Background: Complex fractionated atrial electrograms (CFAE) are a possible target for atrial fibrillation (AF) ablation and can be visualized in three‐dimensional (3D) mapping systems with specialized software. Objective: To use the new CFAE software of CartoXP® (Biosense Webster, Diamond Bar, CA, USA) for analysis of spatial distribution of CFAE in paroxysmal and persistent AF. Methods: We included 16 consecutive patients (6 females; mean 59.3 years) with AF (6 paroxysmal and 10 persistent) undergoing AF ablation. Carto maps of left atrium (LA) were reconstructed. Using the new CFAE software, the degree of local electrogram fractionation was displayed color‐coded on the map surface. LA was divided into four regions: anterior wall, inferior wall, septum, and pulmonary veins (PV). The relationship among regions with CFAE visualized and CFAE ablation regions (persistent AF only) was analyzed retrospectively. Results: In paroxysmal and persistent AF, CFAE were observed in all four LA regions. In paroxysmal AF, the density of CFAE around the PV was significantly higher than in other regions (P < 0.05) and higher than in persistent AF (P < 0.05). In persistent AF, CFAE were evenly distributed all over the LA. Of 40 effective ablation sites with significant AF cycle length prolongation, 33 (82.5%) were judged retrospectively by CFAE map as CFAE sites. Conclusion: CFAE software can visualize the spatial distribution of CFAE in AF. CFAE in persistent AF were observed in more regions of LA compared to paroxysmal AF in which CFAE concentrated on the PV. Automatically detected CFAE match well with ablation sites targeted by operators.     

心房颤动肺静脉前庭和左房内连续碎裂电位的电生理特点

目的探讨阵发性和持续性心房颤动(简称房颤)患者肺静脉前庭(PVO)和左房(LA)内连续碎裂电位(CFEAs)的电生理特点。方法入选24例药物治疗无效的房颤患者,依房颤节律分为阵发性房颤(PAF)组与持续性房颤(PeAF)组,每组各12例,根据距离肺静脉口远近,将肺静脉分成距肺静脉5～10 mm(Ⅰ区)与10～20 mm(Ⅱ区)两区。在房颤时,应用EnSite NavX标测系统高密度标测PVO和LA,比较两组平均CFE值(碎裂间期)≤70ms的CFAEs的电生理特点。结果①PeAF组LA内径大于PAF组(P<0.05),PAF组LA后壁CFAES分布比例最低,顶部最高,PeAF组前后壁最低,左心耳最高;PAF组PVO较LA高(P<0.05),PeAF组PVO和LA无差异。②两组间总PVO区域连续CFAEs比例无差异,PeAF组LA明显高于PAF组(P<0.05),PAF左下PVO连续CFAEs分布比例高于PeAF(P=0.02),另三支PVO无明显差别。除顶部PAF组连续CFAEs分布高于PeAF组(P=0.02)外,PeAF组下壁、左心耳及二尖瓣环均显著高于PAF组(P均<0.001)。③PAF组各支Ⅰ区连续CFAEs分布高于Ⅱ区(P<0.05),PeAF组左下PVOⅠ区高于Ⅱ区(P<0.05),右上PVOⅡ区高于Ⅰ区(P<0.05),另两支PVO无差异。④PAF组PVO平均CFE明显低于LA(P<0.0001),PeAF组两区域及两组间PVO则无差异;PeAF组LA平均CFE值较低,连续CFAEs数量较多,房颤周长较短。结论 LA电解剖重构在房颤维持中起重要作用,PeAF LA内连续CFAEs分布较PAF广泛,碎裂程度更高,房颤周长较短。PVO绝大多数连续CFAEs位于5～10 mm区域。     

Autonomic mechanism to explain complex fractionated atrial electrograms (CFAE)

Objective:  To simulate complex fractionated atrial electrograms (CFAE) during sustained atrial fibrillation (AF) in experimental animals.
Background:  The mechanism(s) underlying CFAE has not been fully elucidated.
Methods:  Twenty-two dogs were subjected to a right and/or left thoracotomy. A gauze patch soaked with acetylcholine (ACh) was placed on the right atrial appendage (RAA) to induce sustained AF. During AF, varying concentrations of ACh (1, 10, 100 mM) were "painted" on the RA where electrograms showed regular organized activity. In another six dogs, anterior right ganglionated plexi (ARGP) near the sino-atrial node and inferior right GP (IRGP) at the junction of inferior vena cava and atria were sequentially ablated. In five dogs, ACh was injected into ARGP to induce CFAE.
Results:  During sustained AF, local "painting" with ACh 1 mM and 10 mM induced intermittent CFAE in 1 of 11 and 10 of 11 dogs, respectively. With 100 mM ACh, all 11 showed CFAE (two intermittent, nine continuous). In six other dogs, continuous CFAE induced by topical application of 100 mM ACh were markedly attenuated by ARGP + IRGP ablation. In another five of five dogs, ACh injection into ARGP induced a gradient of CFAE with the continuous CFAE always occurring near the ARGP and CFAE also occurring at left pulmonary vein-atrial junctions. During ARGP ablation, AF was terminated in all five dogs immediately after regularization of the rotor-like electrograms or continuous CFAE.
Conclusions:  This study demonstrates an autonomic basis for CFAE formation, suggesting that graded hyperactive states of the autonomic nervous system (ANS) may induce various types of CFAE observed clinically.     

Relationship between complex fractionated electrograms (CFE) and dominant frequency (DF) sites and prospective assessment of adding DF-guided ablation to pulmonary vein isolation in persistent atrial fibrillation (AF)

Dominant Frequency Mapping and Ablation . Background: Sites of high DF are potential targets for AF ablation, but it is unknown if addition of DF ablation can improve procedural outcome. Objectives: We sought to (1) examine the relationship between DF sites and complex fractionated electrograms (CFE) and (2) prospectively assess the long‐term outcome of adding DF ablation to pulmonary vein antral isolation (PVAI) for persistent AF. Methods: First, 20 patients with persistent AF who underwent previous CFE‐guided ablation and who had AF terminate during ablation were studied retrospectively (group I). Bipolar, 8‐second electrograms were collected by a circular catheter (288 ± 86 points/map). The EnSite NavX system allows for automated display of both CFE and DF maps. Electrograms with cycle length <120 ms were considered CFE and were compared to DF sites > 8 Hz (direct inverse relationship). Sites of AF termination were related to CFE and DF sites. Based on these observations, 30 different patients (group II) with persistent AF prospectively underwent DF‐guided ablation plus PVAI. They were followed every 3 months for 1 year (visit, Holter, ECG). These patients were compared to case‐matched controls undergoing PVAI alone (group III). Results: In group I, there was a significant, inverse correlation between DF and CFE values at each point (r =–0.24, P < 0.001). DF surface area was less than CFE area (27 ± 5 cm² vs 34 ± 4 cm², P = 0.03). CFE sites overlapped 48 ± 27% with the DF surface area. Nonoverlapping CFE sites were contiguous to DF sites. AF termination occurred where DF and CFE overlapped, and at these sites, DF was always greater than the mean DF for the map. In group II, all DF sites above the mean value were prospectively ablated during AF. AF termination was noted in only 2/30 (7%) patients. After DF ablation, PVAI was performed and termination increased to 4/30 patients (14%). At 1 year, freedom from atrial arrhythmia > 30 seconds occurred in 57% of DF+PVAI compared to 60% in patients receiving PVAI alone (P = 0.18). Conclusions: DF and CFE regions overlap only about 50%. AF termination retrospectively occurred on overlapping CFE/DF sites where DF was above the mean. However, prospective ablation of DF sites plus PVAI resulted in low AF termination rates, and did not improve 1 year success over PVAI alone. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1309‐1316, December 2011)     

Diagnostic accuracy of a new software for complex fractionated electrograms identification in patients with persistent and permanent atrial fibrillation

Introduction: The elimination of complex fractionated atrial electrograms (CFAEs) has been proposed as a potential target for guiding successful AF substrate ablation. The possibility to efficiently map the atria and rapidly identify CFAEs sites is necessary, before the CFAEs ablation becomes a routine approach. The aims of this study, conducted in patients with persistent and permanent atrial fibrillation (AF), were to analyze by CARTO mapping in the right (RA) and in the left atrium (LA) during AF: (1) the diagnostic accuracy of a new software for CFAEs analysis, (2) the spatial distribution of CFAEs, (3) the regional beat to beat AF intervals (FF). Methods and Results: Twenty‐five consecutive patients (four women, 58.8 ± 11.4 years) undergoing radiofrequency catheter ablation for persistent and permanent AF were enrolled in the study. The CFAE software showed a high sensitivity (90%) and specificity (91%) in the identification of CFAEs, using a specific setting of parameters. The LA had a significantly higher prevalence of CFAEs as compared with the RA (30.5% vs 20.3%, P = 0.016). The CFAEs were mostly present in the septum and in the area of coronary sinus ostium (CS os). The FF intervals were significantly shorter in the LA than in the RA (P < 0.01). Conclusion: CARTO system has a high diagnostic accuracy in the identification of CFAEs. Atrial electrical activity (CFAEs, mean FF intervals) during AF showed a significant spatial inhomogeneity.     

慢性心房颤动导管消融:碎裂电位消融和线性消融的比较

目的评价环肺静脉隔离(CPVI)基础上采用心房碎裂电位(CFAEs)消融或(和)线性(Linear)消融进行心房基质改良的疗效。方法回顾性分析156例慢性心房颤动(简称房颤)消融病例,房颤病程2.5±2.3年,左房内径42.4±4.5 mm。根据消融术式改进分为三组CPVI+CFAEs、CPVI+linear和CPVI+CFAEs+Linear组。比较消融术中房颤终止比例及随访疗效。结果三组消融总时间有显著性差异(160±14 min vs 178±9 min vs 241±8min,P<0.01)。CPVI+CFAEs组终止房颤/转变房性心动过速(简称房速)的比例(52.7%)显著高于CPVI+Line-ar组(18.4%),但低于CPVI+CFAEs+Linear组(73.1%)。术后3.1±1.2个月,三组二次消融比例47.3%、51%、38.5%,P=0.43。术后平均随访9.5±1.8个月,三组无房性快速性心律失常复发例数分别为39例(70.9%)、33例(67.3%)和41例(78.8%),P=0.41(服用抗心律失常药物比例25.6%、24.2%和22%,P=0.96)。结论 CP-VI基础上CFAEs消融的房颤终止比例高于单纯线性消融,但低于联合应用CFAEs消融和Linear消融。尽管如此,三组术后二次消融比例和随访成功率无显著性差异。     

Consistency of the CFAE phenomena using custom software for automated detection of complex fractionated atrial electrograms (CFAEs) in the left atrium during atrial fibrillation

Introduction: Complex fractionated atrial electrograms (CFAEs) have been described as a potential target for ablation of atrial fibrillation (AF). The purpose of this study is to assess the consistency of the CFAE phenomena using custom software for automated detection of CFAEs in the left atrium during AF. Methods and Results: This prospective study included 10 patients referred for catheter ablation of symptomatic drug‐refractory AF. Ten consecutive points at a single location (cluster) were acquired as electroanatomical points every 3 seconds. Atrial signals were automatically classified as CFAEs by the software algorithm. The number of intervals between 50 ms and 110 ms and in the voltage range 0.05–0.15 mV during the 2.5‐second recordings was determined and referred to as the interval confidence level (ICL). A total of 2,226 points were acquired during mapping of AF. A dominant group of ICL using one of two different configurations of ICL fractionation was identified. A dominant group was defined as the ICL categorization occurring with greatest frequency in a given cluster of points. The results show the consistency ranged from 73%± 21 for the three‐group configuration (ICL ≤ 4; 4 < ICL ≤ 7; ICL > 7) to 84%± 16 for the two‐group configuration (ICL ≤ 5; ICL > 5). Conclusion: This novel software offers an objective method for CFAE analysis during atrial fibrillation. CFAE consistency ranged from 73% to 84% with wide standard deviation. Automated detection of CFAEs may remove the pitfalls associated with subjective visual detection, thus removing one variable in comparative studies of using CFAEs as AF ablation targets.     

Automated detection and characterization of complex fractionated atrial electrograms in human left atrium during atrial fibrillation

BACKGROUND: Complex fractionated atrial electrograms (CFAEs) have been reported as ablative targets for the treatment of atrial fibrillation (AF). However, the process of CFAE identification is highly dependent on the operator's judgment. OBJECTIVE: It is the aim of the study to report our initial experience with a novel software algorithm designed to automatically detect CFAEs. METHODS: Nineteen patients (6 female, 58 +/- 8 years) who underwent catheter ablation of paroxysmal (n = 11) or persistent (n = 8) AF were included in the study. During ongoing AF, 100 +/- 15 left atrial (LA) endocardial locations were sampled under the guidance of integrated electroanatomical mapping with computed tomographic images. Bipolar electrograms recorded throughout the LA were analyzed using custom software that allows for automated detection of CFAEs. Interval confidence level (ICL), defined as the number of intervals between consecutive CFAE complexes during 2.5-second recordings, was used to characterize CFAEs. The CFAE sites with an ICL >/=5 were considered as sites with highly repetitive CFAEs, which are thought to be potential ablation targets. For purposes of analysis, the LA was divided into 6 areas: pulmonary vein (PV) ostia, posterior wall, interatrial septum, roof, mitral annulus area, and appendage. RESULTS: Among a total of 1,904 LA locations sampled in 19 patients, 1,644 (86%) were categorized as CFAE sites, whereas 260 (14%) were categorized as as non-CFAE sites. Thirty-four percent of all CFAE sites were identified as sites with highly repetitive CFAEs. Of these, 24% were located at the interatrial septum, 22% on the posterior wall, 20% at the PV ostia, 18% at the mitral annulus area, 14% on the roof, and 2.7% at the LA appendage. In all patients, highly repetitive CFAE sites were distributed in 4 or more areas of the LA. Persistent AF patients had more highly repetitive CFAE sites on the posterior wall than paroxysmal AF patients (30% +/- 7.3% vs 14% +/- 8.2%, P < .001). There was a strong trend toward more highly repetitive CFAE sites located at the PV ostia in patients with paroxysmal AF compared with persistent AF patients (24% +/- 13% vs 13% +/- 7.7%, P = .05). CONCLUSION: With the use of custom software, CFAE complexes were identified in more than 80% of the LA endocardial locations. LA sites with highly repetitive CFAE sites were located predominately in the septum, posterior wall, and PV ostia. Patients with persistent AF had a different anatomical distribution pattern of highly repetitive CFAE sites from those with paroxysmal AF, with a greater prevalence of highly repetitive CFAEs located on the posterior wall. Further studies are warranted to determine the clinical significance of these findings.     

肺静脉电隔离术联合碎裂电位消融治疗持续性房颤疗效观察

目的：观察肺静脉电隔离术（ pulmonary vein isolation , PVI ）联合碎裂电位（ complex fractionated atrial electrograms , CFAE）消融对持续性房颤的疗效。方法对比观察23名于本院行房颤射频消融术的持续性房颤患者,所有患者均行PVI及左房顶部线性消融,其中12例联合CFAE消融,术后随访1年;观察两组手术时间、X线曝光时间、消融时间、手术并发症、左房大小、左房血栓、一次手术成功率等指标。结果联合CFAE消融组总手术时间（252±35） min、X线曝光时间（42±9．1）min、消融时间（94±11）min,单纯行PVI 组分别为（176±22）min、（34±7．6）min、（63±8）min,联合CFAE消融组手术各时间均明显延长（P＜0．01）;两组手术并发症、对左房大小及左房血栓的影响比较差异均无统计学意义;联合CFAE消融组一次手术成功率（75％）明显高于单纯行PVI组（64％）（ P＜0．05）。结论 PVI联合CFAE消融治疗持续性房颤虽增加手术、消融及X线曝光时间,但并不会提高并发症发生率,可提高房颤消融的一次手术成功率。     

Ablation of left atrial tachycardia with cycle length alternans after atrial fibrillation ablation: significance of fractionated electrogram mapping

Introduction

Atrial tachycardia (AT) with cycle length alternans occurring after atrial fibrillation ablation has not been previously described.

Methods

Among 66 patients with left AT, stable AT with 2 alternating cycles was registered in 5 cases. Activation mapping of both alternating cycles was performed in all 5 patients. Entrainment and fractionated electrogram mappings were also carried out.

Results

Among 10 AT cycles, activation maps suggested underlying mechanism of 5 cycles (50%) in 3 patients. Entrainment pacing was helpful in 2 patients (confirmed mechanism of 2 AT cycles). Catheter ablation successfully terminated AT in all 5 patients: ablation of sites with fractionated potentials in 4 patients and mitral isthmus ablation in 1 patient.

Conclusion

Consecutive activation mapping of both AT cycles is feasible for mechanism determination in some patients. The results of our small study suggest that fractionated electrogram-guided ablation might be a reasonable approach for termination of this type of AT.     

单纯碎裂电位指导心房颤动消融的初步临床观察

目的探讨碎裂电位指导心房颤动（房颤）射频导管消融的可行性。方法22例药物治疗无效有症状的房颤患者（阵发性16例,持续性6例）,在自发或诱发房颤时,用Carto构建左心房或左、右心房的三维模型并标测、消融碎裂电位,终点是消除标测到所有碎裂电位或转复窦性心律。结果碎裂电位消融后,13例（59％）转复为窦性心律（直接转复7例,先转为房性心动过速（房速）／心房扑动（房扑）然后转复6例）,9例消融未转复窦性心律患者行电复律或药物复律成功。6例复发（5例房速／房扑,1例阵发性房颤）再次消融,5例成功,随访3—18（10．9±4．8）个月,共有16例（73％）无快速房性心律失常事件,碎裂电位主要分布于左侧房间隔、肺静脉周围、左心房顶部。碎裂电位消融后房颤终止前房颤周期与碎裂电位消融前相比明显延长[（157±18）ms vs （211±32）ms,P〈0．05]。除一例发生心脏压塞且心包穿刺成功引流外,无消融术相关的并发症和后遗症。结论碎裂电位指导房颤导管射频消融安全有效可行。     

不同部位刺激诱发心房颤动时碎裂电位的出现与分布

目的 探讨在心房和肺静脉不同部位行电刺激诱发心房颤动（简称房颤）时碎裂电位（CFAEs）的出现与分布。方法 22只成年健康杂种犬,常规麻醉,气管插管,切断双侧颈迷走神经干,破坏颈交感神经节,建立动物的去自主神经模型。双侧开胸,分别在右心耳、左心耳和四支肺静脉的近、中、远段行电刺激诱发房颤,观察在基础刺激、双侧强迷走刺激两种诱发条件下,房颤发作时CFAEs的分布情况。结果 刺激诱发房颤的部位与CFAEs出现的部位并不完全一致。双侧心房（心耳）及肺静脉口附近是房颤时CFAEs出现的高频部位。当伴有迷走神经刺激时,房颤的诱发率提高,CFAEs的出现频率也随之明显增加。结论 房颤时CFAEs的分布并不局限于心房或肺静脉的某一局部区域,而是在多个部位可同时标测到。迷走刺激条件下标测到CFAEs的频率增加。     

Radiofrequency ablation of complex fractionated atrial electrograms (CFAE): preferential sites of acute termination and regularization in paroxysmal and persistent atrial fibrillation

Introduction: Complex fractionated atrial electrograms (CFAE) have been described as a new target for ablation of atrial fibrillation (AF). This prospective study evaluates the acute effects of CFAE ablation in patients with paroxysmal or persistent AF and analyzes the preferential anatomic sites where these effects occur.
Methods and Results: Ablation of CFAE was performed in 66 symptomatic patients (mean age of 58 ± 12 years) with paroxysmal (n = 36) or persistent AF (n = 30). Termination or regularization of AF during ablation of CFAE was achieved in 56 of 66 patients (84%), with termination in 28 of 66 patients (42%) and regularization of AF in 28 of 66 patients (42%). Ablation of CFAE showed no effect in 10 of 66 patients (16%). Termination of AF occurred at 53 sites and AF regularization at 81 sites. The preferential sites of AF termination or regularization were found around the pulmonary veins (termination n = 15; regularization n = 22), at the anterior wall (termination n = 14; regularization n = 19) and at the interatrial septum (termination n = 8; regularization n = 17).
Conclusion: Termination or regularization of AF was achieved acutely in 84% of patients by ablation of CFAE. The preferential sites of AF termination or regularization were found around the pulmonary veins, at the anterior wall of the LA and at the interatrial septum. These findings may have implications for future ablation concepts.