Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.     

A Clinical Study of Patients with and Without Recurrence of Paroxysmal Atrial Fibrillation After Pulmonary Vein Isolation

Patients with paroxysmal atrial fibrillation (PAF) can be treated by pulmonary vein (PV) isolation. However, the recurrence rate after this procedure is relatively high. We sought to evaluate the quality of life (QOL) of patients with PAF recurrence after PV isolation and to analyze factors related to recurrences. Seventy-two drug-refractory PAF patients (59 men, 13 women, mean age 52 ± 10) were included. PV isolation was based on the disappearance of PV potentials recorded from a Lasso catheter after segmental ostium ablation. Automatic foci were observed in 47 patients (65.3%) during the procedure. A mean of 3.1 ± 0.9 PVs was isolated. Patients were followed for a mean of 10.3 ± 5.1 months, during which 27 experienced >1 episode of PAF. QOL was scored from 0 (situation before ablation) to 10 (no episode after ablation) based on a questionnaire completed by 69 patients (95.8%). QOL was judged very good in 26 patients (none with PAF recurrences), better in 30 (15 with PAF recurrences), unchanged in 11 (10 with recurrences), and worse in 2 patients with PAF recurrences. Longer histories of PAF and a lower percentage of patients with automatic foci identified during the procedure were observed in the group with, than in the group without recurrences (P < 0.05). PV isolation improved QOL in patients with PAF, including in patients with recurrences. The length of PAF history and observation of automatic foci may be of importance for recurrences of PAF during long-term follow-up.     

A New Nonfluoroscopic Navigation System to Guide Pulmonary Vein Isolation

Different techniques have been proposed to treat atrial fibrillation (AF) by catheter ablation. This study compares a new three-dimensional (3D) nonfluoroscopic navigation system with conventional fluoroscopy to guide pulmonary vein (PV) isolation. A total of 60 consecutive patients with paroxysmal or persistent AF were randomly assigned to 3D-guided ablation (group 1, n = 30), versus conventional fluoroscopy guidance ablation (group 2, n = 30). Complete PV isolation was achieved in both groups. The mean duration of fluoroscopy exposure (22 ± 8 vs 56 ± 10 minutes), and radiofrequency delivery (5 ± 1 vs 10 ± 3 minutes) were significantly shorter in group 1 than in group 2, P < 0.05 for both comparisons). The mean procedural time in group 1 was longer (225 ± 15 minutes) than in group 2 (156 ± 10 minutes, P < 0.05) due to the learning curve and time spent to generate the 3D maps. Over a mean follow-up of 7 ± 2 months, 6 patients (20%) in group 2 had AF recurrences compared to 3 patients (10%) in group 1 (ns). The new nonfluoroscopic 3D system allows a high-resolution reconstruction of the left atrium and PVs. It significantly reduces the mean radiofrequency delivery and fluoroscopy times as opposed to ablation performed under fluoroscopy guidance.     

Computational Method to Predict Esophageal Temperature Elevations During Pulmonary Vein Isolation

Background: The esophagus is in close proximity to the posterior wall of the left atrium, which renders it susceptible to thermal injury during radiofrequency (RF) ablation procedures for atrial fibrillation (AF). Real‐time assessment of esophageal position and temperature (T °) during pulmonary vein (PV) isolation has not been extensively explored. Objective: To develop a protocol that allows estimation of the potential for, and avoidance of, esophageal heating. Methods: In consecutive patients who underwent PV isolation, a thermal probe was used to monitor T ° fluctuations in the esophagus during application of RF energy. The tip of the thermal probe was positioned at the level of the targeted PV and RF was discontinued for T ° rise >0.5°C. The proximity of individual PVs to the esophagus was measured from the temperature probe tip to the closest posterior part of the Lasso catheter from review of biplane projections (left anterior oblique 60° and right anterior oblique 30°). These raw distances were entered into the Pythagorean theorem and the actual distance between the esophageal thermal probe and PV antrum was determined. Results: The study cohort included 44 patients (60 ± 11 years, 61% male, 57% lone AF). The thermal probe in the esophagus was closer to the left‐sided PVs (left common pulmonary vein: 20.9 ± 13 mm, left upper pulmonary vein: 20.5 ± 11 mm, left lower pulmonary vein: 23.4 ± 10 mm) than the right‐sided ones (right common pulmonary vein: 31.0 ± 11 mm, right upper pulmonary vein: 41.9 ± 18 mm, right lower pulmonary vein: 34.5 ± 16 mm). A T ° increase >0.5°C occurred during 116/1,495 (7.8%) deliveries. A T ° rise was more likely during ablation of left‐sided PVs than right‐sided PVs (55% vs 10%, P < 0.0001) and when RF was delivered ≤24 mm from the esophagus (sensitivity 91%, specificity 81%, positive predictive value 75%, and negative predictive value 93%). Conclusion: A thermal probe placed in the esophagus provides real‐time T ° monitoring and anatomic localization. A T ° rise is more likely during ablation of left PVs and during RF deliveries within 24 mm of the esophageal thermal probe. (PACE 2010; 33:1239–1248)     

ATP Revealed Extra Pulmonary Vein Source of Atrial Fibrillation after Circumferential Pulmonary Vein Isolation

Noninducibility of atrial fibrillation (AF) by additional electrograms‐guided ablation may benefit the clinical outcome. This report illustrates the effect of adenosine triphosphate (ATP) injection on AF inducibility after pulmonary vein (PV) isolation. AF was triggered twice by ATP without PV reconnection. Meanwhile, complex fractionated atrial electrograms (CFAEs) were observed, and ablation targets on these sites appeared to be essential to the AF elimination. It suggests that CFAEs may contribute to the initiation of some AF. ATP may be useful to induce AF after proven PV isolation, and further ablation might be necessary to ensure efficacy after circumferential PV isolation. (PACE 2010; 33:248–251)     

Very Late Relapse of Atrial Fibrillation after Pulmonary Vein Isolation: Incidence and Results of Repeat Ablation

Background: There are few data about the incidence of very late (>12 months) arrhythmia relapse after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) and about the success rate of repeat ablation procedures in this population. Methods: All patients treated with PVI for paroxysmal AF were screened in the institution's electrophysiology database. Follow‐up data at 1, 3, 6, and 12 months and yearly thereafter including repetitive (7 days or 1 day) Holter electrocardiograms were assessed as well as the technique and success rate of repeat ablations. Results: Overall, 24 of 356 (6.7%) patients experienced their first AF recurrence more than 12 months after PVI. Of these 24 patients, 14 underwent reablation for paroxysmal (11 patients) or persistent AF (three patients). Repeat ablation included re‐PVI in all 14 patients (43 of 48 initially isolated PVs with recovered left atrial–PV conduction). Ablation of complex fractionated atrial electrograms or left/right atrial lines was performed in eight patients, including the three patients with persistent AF. During follow‐up of 15.1 ± 9 months after the second ablation, 10 of 14 (71%) reablated patients remained in sinus rhythm. Conclusions : After PVI for paroxysmal AF, very late arrhythmia recurrence occurs in less than 10% of patients. The success rate of the repeat procedure is high. (PACE 2010; 33:1258–1263)     

Atrial Flutter Ablation in Inducible Patients during Pulmonary Vein Atrum Isolation: A Randomized Comparison

Background: The incidence of atrial flutter (AFL) post pulmonary vein antrum isolation (PVAI) in patients with atrial fibrillation (AF) is reported to be between 8% and 20%. The need for right or left AFL ablation during the initial PVAI procedure remains controversial. We prospectively compared mapping and ablation versus no ablative treatment of inducible AFL during PVAI. Methods and Results: In 220 patients (167 men, mean age 56 ± 15 years) with symptomatic AF presenting for PVAI, burst pacing from the high right atrium and coronary sinus was performed to determine AFL inducibility. A total of 25 patients with sustained (17 patients) or reproducible (eight patients) AFL were included in this study. Patients were randomized to mapping and ablation of AFL using the CARTO 3D mapping system (Biosense Webster, Diamond Bar, CA, USA) versus no further ablation. Typical AFL was induced in 48% of the patients. During a follow‐up of 12 ± 4 months, recurrences were determined by serial 48‐h Holter and event monitors. Recurrence rates, time to recurrence, and AFL cycle length differences between both groups were not statistically significant. Conclusion: These data suggest that inducibility of AFL post PVAI does not predict long‐term incidence of AFL. Moreover, this study demonstrates little benefit to mapping and ablation of these arrhythmias during the PVAI procedures.     

Role of Pulmonary Veins Isolation in Persistent Atrial Fibrillation Ablation:

Background: The role of pulmonary veins (PV) isolation in patients with persistent atrial fibrillation (AF) is still debated. The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation (anatomical approach).
Methods: We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach (group A, n = 36, mean age = 60 ± 8 years, 29 males) or an integrated approach (group B, n = 61, mean age 59 ± 10 years, 48 males). In all patients, radiofrequency (RF) ablation was performed by means of a nonfluoroscopic navigation system, in order to anatomically create circumferential lines around the PV. In group B, the persistence of PV potentials was ascertained with a multipolar circular catheter. If PV potentials persisted, RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV. Past a 2-month period of observation, success was defined as absence of any atrial tachyarrhythmia recurrence lasting >30 seconds.
Results: Total procedure duration (220 ± 62 minutes vs 140 ± 43 minutes, P < 0.001), fluoroscopy time (35 ± 15 minutes vs 17 ± 9 minutes, P < 0.001), and RF delivery time (48 ± 22 minutes vs 27 ± 9 minutes, P < 0.001) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 ± 9.1 months, 21 patients in group A (58%) and 34 patients in group B (56%) were free of atrial tachyarrhythmia recurrence (P = 0.9).
Conclusions: In patients with persistent AF, who underwent an anatomical approach, electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times, without effect on the long-term outcomes.     

Atrio-Pulmonary Vein Conduction Delay during Pulmonary Vein Isolation for Atrial Fibrillation Is Related to Vein Anatomy, Age, and Focal Activity

Background: During pulmonary vein isolation for treatment of atrial fibrillation (AF), a significant delay in atrio-pulmonary vein (PV) conduction is often observed. We sought to investigate this conduction delay in various PV in individual patients.
Methods: We studied 385 AF patients (mean age: 54 ± 11 years, 74 women) who underwent segmental PV isolation (PVI). A circular decapolar catheter was used to record electrograms at the PV ostia. The time delay from local atrial potential to PV potential was measured in each vein. Conduction delay (CD) was defined as the longest time interval >20 ms observed during PVI.
Results: For patients treated for the first time, CD was more frequently observed in the left common and the right and left superior PVs (84.2%, 67.9%, and 66.2%, respectively) and less frequently in the left and right inferior and right middle PVs (54.3%, 40.0%, and 30.8%, respectively). Veins with CD required more ablation applications (12.4 vs 9.9) and a higher ablated segmental fraction (72.3% vs 63.7%). CD was observed in 75.2% (109/145) of the PVs in which focal activity was detected. Older patients had a higher incidence of PVs with CD than younger patients. There were no gender differences.
Conclusions: The incidence of CD was highest in the left common and superior PVs, in older patients and in PVs with focal activity. PVs with CD required more ablation applications and a larger area of ablation around the ostia. These observations were not found during repeat procedures.     

阵发性心房颤动的环肺静脉电隔离单环消融及双环消融术的比较

目的 比较环肺静脉电隔离单环消融和双环消融治疗阵发性心房颤动(简称房颤)的疗效.方法 将40例抗心律失常药治疗无效或出现严重不良反应的阵发性房颤患者,按随机数字表法分为单环消融组和双环消融组,每组20例.单环消融组距肺静脉口0.5 cm作肺静脉单环电隔离线;双环消融组距肺静脉口0.5 cm和1 cm处,分别作肺静脉单环电隔离线.对2组患者手术时间、X线曝光时间,术后6、12个月治愈情况及肺静脉狭窄并发症的发生进行比较.结果 术前2组年龄,房颤发病时间、发作频率,左房内径等比较差异均无统计学意义(均P＞0.05).2组手术时间、术中X线曝光时间比较差异均无统计学意义(均P＞0.05).术后6个月,双环消融组的一次手术治愈率为90％,高于单环消融组的80％(P＜0.05);术后12个月,双环消融组二次手术治愈率为95％,明显高于单环消融组的二次手术治愈率的90％ (P＜0.05).术后6个月2组均未发生肺静脉狭窄.结论 环肺静脉电隔离双环消融治疗阵发性房颤较单环消融效果好.     

Pathophysiology of the Pulmonary Vein as an Atrial Fibrillation Initiator:

The basic electrophysiologic studies have proved the arrhythmogenic mechanisms of the pulmonary vein as an atrial fibrillation initiator; the mechanisms include enhanced automaticity, triggered activity, and microreentry from myocardial sleeves inside pulmonary veins. Immunohistology study has proved the conduction characteristics of pulmonary vein myocardium, and further study of ionic currents are important for understanding atrial fibrillation initiation from the pulmonary vein. (PACE 2003; 26[Pt. II]:1576–1582)     

The Anatomic Impact of Sequential,Additional, Ostial Radiofrequency Ablation Following Pulmonary Vein Cryo‐Isolation

Background : Although pulmonary vein (PV) stenosis is a serious complication of radiofrequency PV isolation, the anatomical impact of a combination of two energy sources on PV diameter has not been evaluated. The aim of this study was to evaluate the impact of supplementary point‐by‐point radiofrequency applications (following PV cryoablation) on the PV orifice diameter. Methods : Forty‐nine patients having undergone PV isolation for drug‐refractory atrial fibrillation were included. All had undergone cardiac computed tomography before ablation and again at least 3 months afterwards. When isolation with the cryoballoon was not complete, a conventional irrigated‐tip radiofrequency catheter was used for point‐by‐point applications. Results : Of the 189 target PVs, 117 were isolated with cryotherapy alone (cryo PVs) and 72 required additional radiofrequency (hybrid PVs). The second scan (performed an average of 11.4 ± 5.4 months after) showed a decrease in diameter for all the hybrid PVs (17.2 ± 2.6 to 16.3 ± 3.4 mm; P = 0.037) but no change for the cryo PVs. This change was associated with a decrease in left superior pulmonary vein (LSPV) diameter (19.2 ± 3.0 to 17.8 ± 4.9 mm, P = 0.014). There were no changes in other veins. A subgroup analysis for the LSPV revealed a decrease for the hybrid PVs (18.8 ± 3.6 to 15.9 ± 7.1 mm, P = 0.046) but not for the cryo PVs. Significant PV stenosis was observed in three hybrid PVs (two severe stenosis of the LSPV and one moderate stenosis of the right inferior pulmonary vein) but not in cryo PVs (4.1% vs 0%, respectively; P = 0.023). Conclusions : Cryoballoon ablation of the PV with adjunct, focal, irrigated ostial RF applications may be associated with a higher risk of PV stenosis. (PACE 2012;35:1420–1427)     

Two-to-one Conduction Block Between Left Atrium and Right Lower Pulmonary Vein Preceding Complete Vein Isolation During Radiofrequency Current Ablation

A 56-year-old patient with paroxysmal atrial fibrillation who developed a transient 2:1 block between the left atrium and right inferior pulmonary vein during a single application of radiofrequency current was described. The production of transient and complete atriovenous block by a single application of radiofrequency current demonstrates that a single connection between the pulmonary veins muscle and the left atrium may exist. (PACE 2004; 27[Pt. I]:829–830)