Circumferential mapping and electric isolation of pulmonary veins in patients with atrial fibrillation

Information about the clinical efficacy and complications of the circumferential mapping and isolation of the pulmonary veins (PVs) in patients with atrial fibrillation (AF) is still limited. The present study included 75 patients (mean age 58 +/- 11 years, 20 women) with paroxysmal (n = 69) or persistent AF (n = 6). Mapping of PVs was performed with a circumferential mapping catheter. After preferential PV-left atrium (LA) electric inputs were defined, radiofrequency ablation was performed until complete isolation of the PVs from the LA was achieved. A total of 226 PVs were mapped; 195 (86%) showed typical PV potentials. Complete isolation of PVs from the LA was achieved in 173 PVs (89%). Detailed follow-up, including 7-day Holter monitoring at 1, 4, 9, and 12 months after intervention was performed. If AF reoccurred, PVs were mapped and reisolated. After a mean follow-up period of 230 +/- 133 days, 38 of 75 patients (51%) were in sinus rhythm. At 1, 4, and 9 months of follow-up, 31 of 65 patients (48%), 36 of 53 patients (68%, p = 0.04 as compared with the first month), and 21 of 28 patients (75%, p = 0.025 as compared with the first month), respectively, were in sinus rhythm. During follow-up, 30 patients (40%) underwent a second ablation procedure due to recurrence. Recurrences were related to resumption of PV muscle-left atrial conduction (27 patients) and/or extra PV foci (12 patients) or nonablated PVs (8 patients). Complications occurred in 17 patients (22%). PV stenosis was detected in 13 patients (25% to 50% in 7 patients and >50% in 6 patients). Pericardial effusion occurred in 4 patients. It was concluded that isolation of the PV from the LA is moderately effective in the prevention of AF recurrence and could be associated with serious acute and long-term complications.     

阵发性心房颤动患者肺静脉与心房电连接特征的临床研究

目的 总结阵发性心房颤动(房颤)患者肺静脉的电生理标测和导管射频消融电隔离的结果，评估中国人肺静脉与心房的电连接类型和特点。方法 顽固性阵发性房颤患者43例，在环状标测电极指导下行肺静脉电位(PVP)记录和分析，并对能标测到PVP的肺静脉进行开口部的点或段的消融电隔离治疗。根据窦性心律和心房起搏下的肺静脉内环形标测电报导管标测到的PVP的激动顺序，以及有效放电对PVP的影响，分析和总结肺静脉与心房之间的电连接特点。结果 共标调和域电隔离肺静脉100根，其中呈单束状电连接35根(35％)，双束状电连接48根(48％)，多束状电连接11根(11％)，环状电连接3根，无电连接3根。结论 根据环状电报标测到的PVP激动顺序和对放电的反应，提示肺静脉与心房之间电连接的类型多为单束状和双束状(83％)，说明对于大多数肺静脉不必进行环状消融，而只需在肺静脉与心房连接处进行点状或节段性消融即可达到完全电隔离的效果。     

Frequency mapping of the pulmonary veins in paroxysmal versus permanent atrial fibrillation

Introduction: The pulmonary veins (PVs) are a dominant source of triggers initiating atrial fibrillation (AF). While recent evidence implicates these structures in the maintenance of paroxysmal AF, their role in permanent AF is not known. The current study aims to compare the contribution of PV activity to the maintenance of paroxysmal and permanent AF.
Methods and Results: Thirty-four patients with paroxysmal AF (n = 20) or permanent AF (n = 14) undergoing ablation were studied. Prior to ablation, 32 seconds of electrograms were acquired from each PV and the coronary sinus (CS). The frequency of activity of each PV and CS was defined as the highest amplitude frequency on spectral analysis. The effects of ablation on the AF cycle length (AFCL) and frequency and on AF termination were determined. Significant differences were observed between paroxysmal and permanent AF. Paroxysmal AF demonstrates higher frequency PV activity (11.0 ± 3.1 vs 8.8 ± 3.0 Hz; P = 0.0003) but lower CS frequency (5.8 ± 1.2 vs 6.9 ± 1.4 Hz; P = 0.01) and longer AFCL (182 ± 17 vs 158 ± 21 msec; P = 0.002), resulting in greater PV to atrial frequency gradient (7.2 ± 2.2 vs 4.2 ± 2.9 Hz; P = 0.006). PV isolation in paroxysmal AF resulted in a greater decrease in atrial frequency (1.0 ± 0.7 vs −0.05 ± 0.4 Hz; P < 0.0001), greater prolongation of the AFCL (49 ± 35 vs 5 ± 6 msec; P < 0.0001), and more frequent AF termination (11/20 vs 0/14; P = 0.0007) compared to permanent AF.
Conclusion: Paroxysmal AF is associated with higher frequency PV activity and lesser CS frequency compared to permanent AF. Isolation of the PVs had a greater impact on the fibrillatory process in paroxysmal AF compared to permanent AF, suggesting that while the PVs have a role in maintaining paroxysmal AF, these structures independently contribute less to the maintenance of permanent AF.     

Reentrant tachycardia in pulmonary veins of patients with paroxysmal atrial fibrillation

INTRODUCTION: Although slow automatic pulmonary vein (PV) activity dissociated from the atrium after achievement of PV isolation in patients with atrial fibrillation (AF) has been reported, little is known about dissociated PV tachycardia. The aim of this study was to investigate the inducibility and the mechanism of sustained PV tachycardia (SPVT). METHODS AND RESULTS: One hundred thirty-two patients with drug-refractory paroxysmal AF underwent PV isolation by radiofrequency catheter ablation. Programmed stimulation was performed in 269 PVs of 110 of these patients after achievement of PV isolation. In 7 PVs (2.6%; left superior PV: n = 2, right superior PV: n = 4, right inferior PV: n = 1) of 7 (6.4%) of 110 patients, 18 SPVTs were induced. Fifteen regular SPVTs (mean cycle length 152 +/- 34 msec) were induced in 6 of 7 PVs, and 3 irregular SPVTs (cycle length range: 94-276 msec) were induced in 3 of 7 PVs. In 2 PVs, both regular and irregular SPVTs were induced. SPVT was terminated by burst pacing in 4 PVs, and entrainment was observed during regular SPVT in 5 PVs. Slow PV automatic activity dissociated from the atrium and decremental conduction properties were shown in all 7 PVs. The shortest pacing cycle length with 1:1 capture was < or =150 msec in 6 of 7 PVs. CONCLUSION: Reentrant tachycardia can occur in some isolated PVs with both decremental conduction properties and short refractory periods, which suggests that reentry may be one of the mechanisms of PV arrhythmogenicity.     

Factors predicting success in cryoablation of the pulmonary veins in patients with chronic atrial fibrillation.

BACKGROUND: This study was designed to investigate the factors predicting maintenance of sinus rhythm (SR) in patients with chronic atrial fibrillation (AF) undergoing cryoablation of the pulmonary veins (PV-cryo) during cardiac surgery. METHODS AND RESULTS: Seventy-seven patients with AF undergoing PV-cryo were recruited and divided into 2 groups based on whether they were able to maintain SR at discharge. The duration of AF (AF-D), left atrial dimension (LAd), and the average of the peak left atrial appendage outflow velocities (LAA-V) before surgery were determined for both groups. Group SR consisted of 54 patients (70%), and group AF consisted of 23 patients (30%). All patients with an AF-D 40 cm/s were in group SR and all those with an AF-D >10 years and LAd >or=65 mm were in group AF. Only 71% of patients with a LAA-V 相似文献   

阵发性心房颤动患者心房及肺静脉不应期离散度的变化

目的探讨阵发性房颤患者房颤相关组织的电生理特性改变情况。方法选取阵发性房颤患者10例(房颤组)和无房颤病史的左侧旁路有显性预激波患者15例(对照组)。将大头电极分别放置在两组患者左上肺静脉、左下肺静脉、右上肺静脉、右下肺静脉开口及左心房顶壁、前壁、后壁、高位右心房,分别测定各部位有效不应期(EPR)。结果①房颤组心房及肺静脉EPR离散度指数(DI)为0.117±0.028,对照组为0.074±0.029,两组比较,P<0.05。②房颤组左心房ERP为(234.00±28.72)ms,肺静脉ERP为(230.75±32.69)ms;对照组左心房ERP为(248.00±25.99)ms,肺静脉ERP为(244.33±26.78)ms,两组比较,P均<0.05。结论阵发性房颤患者DI明显增大,左心房、肺静脉ERP显著缩短。     

Different patterns of atrial activation in idiopathic atrial fibrillation: simultaneous multisite atrial mapping in patients with paroxysmal and chronic atrial fibrillation

OBJECTIVES: We aimed to evaluate: 1) the behavior of electrical activity simultaneously in different atrial regions during atrial fibrillation (AF); 2) the difference of atrial activation between paroxysmal and chronic AF; 3) the atrial refractoriness dispersion; and 4) the correlation between the effective refractory periods (ERPs) and the FF intervals. BACKGROUND: Little data exist on the electrophysiologic characteristics of the different atrial regions in patients with AF. A more detailed knowledge of the electrical activity during AF may provide further insights to improve treatment of AF. METHODS: Right and left atria were extensively mapped in 30 patients with idiopathic AF (18 paroxysmal and 12 chronic). In different atrial locations, we analyzed 1) the FF interval duration; and 2) the grade of organization and, in case of organized electrical activity, the direction of atrial activation. Furthermore, in patients with paroxysmal AF, we determined the atrial ERP, evaluated the ERP dispersion and assessed the presence of a correlation between the ERPs and the FF intervals. RESULTS: In patients with chronic AF, we observed a shortening of the FF intervals and a greater prevalence of disorganized activity in all the atrial sites examined. In patients with paroxysmal AF, a significant dispersion of refractoriness was observed. The right lateral wall showed longer FF intervals and more organized atrial activity and, unexpectedly, the shortest mean ERPs. In contrast, the septal area showed shorter FF intervals, greater disorganization and the longest mean ERPs. CONCLUSIONS: Electrical activity during AF showed a significant spatial inhomogeneity, which was more evident in patients with paroxysmal AF. The mean FF intervals did not correlate with the mean ERPs.     

环状电极标测指导射频消融治疗肺静脉起源的阵发性房颤

背景　常规方法标测射频消融治疗局灶性房颤常导致较长的手术时间及较低的成功率。环状电极标测指导射频消融能够克服这些缺点。目的　评价在 10极环状电极标测指导下射频消融电隔离肺静脉治疗阵发性房颤的可行性和有效性。方法　本组研究包括 16例抗心律失常药物治疗无效的阵发性房颤患者 [男性 11例 ,女性 5例 ,平均年龄 (5 1± 14 5 )岁 ]。 10极的环状标测电极在窦性心律或者冠状窦远端 (CSd)起搏的情况下标测肺静脉 ,确定房性早搏发生的起源 ;一旦确定靶肺静脉 ,肺静脉电位的分布及其激动顺序进行评价 ,射频消融在肺静脉口最早激动处进行。消融终点设定为 :①肺静脉电位消失 ;②肺静脉电位与心房电位无关 ;③房早消失。结果　本组研究总共消融了 36条肺静脉 ,包括 16条左上肺静脉 ,12条右上肺静脉 ,7条左下肺静脉 ,1条右下肺静脉。有 2例消融了 1条肺静脉 ;8例消融了 2条肺静脉 ;5例消融了 3条肺静脉 ;消融 4条肺静脉者 1例。手术时间以及X线曝光时间分别为 (186 7± 6 3 8)min及 (5 1 5± 15 0 )min。在随访的 1～ 12月 ,11例 (6 8 7% )在未服抗心律失常药没有房颤发作 ,其中 2例为再次手术 ,有效者 3例 (18 7% ) ,2例未成功 (12 6 % )。初次术后有 2例发作房早 ,其中 1例服用胺碘酮 ,另外 1     

Relationship between arrhythmogenic pulmonary veins and the surrounding atrial substrate in patients with paroxysmal atrial fibrillation

Arrhythmogenic PVs and the Fibrillatory Activities . Introduction: The relationship between pulmonary veins (PVs) with atrial fibrillation (AF) initiating triggers and their surrounding atrial substrate has not been elucidated. We aimed to clarify the atrial substrate properties around the PVs. Methods and Results: Twenty‐three paroxysmal AF patients were studied with the identification of PV initiating triggers. High‐density mapping of the dominant frequency (DF, 1200 Hz) and the mean degree of the complex fractionated electrograms (CFE mean interval over 6 seconds) was evaluated in 2 zones (zone 1: < 5 mm, zone 2: 5–15 mm from the PVs) and the left atrial (LA) using a NavX system prior to the PV isolation. High‐DFs (>8 Hz) and continuous CFEs (<50 ms) were identified in 1.5 ± 0.9 and 2.3 ± 1.1 regions per patient, respectively. Most of the high‐DF regions (86%) and continuous CFE regions (77%) were located within 15 mm of the PV ostia. Of those, 75% of the high‐DF regions and 54% of the continuous CFE regions were related to arrhythmogenic PVs. There was a significant DF gradient from arrhythmogenic PV zone 1 to zone 2, while the mean CFE exhibited a significant gradient between arrhythmogenic PV zone 2 and the rest of the LA. Additionally, 69% of the procedural AF termination sites were at arrhythmogenic PV zone 2. Conclusion: Evaluation of the atrial substrate properties may be useful for locating arrhythmogenic PVs during AF and defining the extent of the circumferential PV isolation. (J Cardiovasc Electrophysiol, Vol. 22, pp. 405‐410)     

Electroanatomic mapping of right atrial activation in patients with and without paroxysmal atrial fibrillation

Inter-atrial conduction delay in patients with atrial fibrillation (AF) has been reported. However, the area of this conduction delay has not been well identified. The activation time and conduction velocity over the right atrial endocardium were evaluated during sinus rhythm using the CARTO mapping technique in 6 patients with paroxysmal AF (AF group) and 11 patients without history of AF (control group). No significant differences were observed between the 2 groups in the mean activation times and conduction velocities from the earliest activation site to the superior septum, His bundle area and coronary sinus ostium, or in the total activation times of the right atrium. There was no significant difference between the two groups in the local conduction velocity between 2 adjacent sites in the free wall, septum and bottom of the right atrium. This study suggests the previously reported conduction delay in the posteroseptal region in patients with paroxysmal AF might locate within the posterior inter-atrial septum.     

冷冻消融隔离肺静脉治疗阵发性心房颤动的远期随访结果

导管消融已成为心房颤动(房颤)的重要治疗手段.对于阵发性房颤患者,肺静脉隔离仍是最主要的消融策略.但要达到充分的电隔离,往往需要较多的消融能量,造成肺静脉狭窄等并发症的风险增加.应用冷冻消融导管等新器材有望增加成功率,并降低并发症的发生率.本文报道我中心采用环形冷冻消融导管隔离肺静脉治疗阵发性房颤的远期随访结果.     

Simultaneous catheter mapping of the pulmonary veins in focal atrial fibrillation: significance of rapid focal activation,effectiveness for catheter ablation

Most focal atrial fibrillation (AF) is initiated by premature beats from the pulmonary veins (PV), and ablation of these foci can effectively cure AF. We investigated the efficacy of focal ablation and the role of rapid focal activation (RFA) in the maintenance of AF using simultaneous multisite catheter mapping in four PVs. Forty-two patients with frequent attacks of paroxysmal AF were included in the study population. Bipolar electrograms were simultaneously recorded from all four PVs. RFA was determined at AF onset, during sustained AF, or just before the spontaneous termination of AF. RFA was continuously observed not only at a triggered PV, but also at all sites including an opposite non-triggered PV, coronary sinus and high right atrium in sustained AF (>10 minutes), whereas RFA was observed only in the triggered PV and not at the other sites in nonsustained AF. Once RFA ceased, AF terminated immediately. After a mean follow-up of 21 months, focal ablation had eliminated AF without drugs in 24 patients (57%). The technique of simultaneous mapping of the PV using microcatheters is a feasible and effective method for mapping and ablation of focal AF originating from the PV. RFA arising from PVs is important not only as a trigger of onset, but also in the maintenance of AF.