Efficacy of extended antrum ablation based on substrate mapping plus pulmonary vein isolation in the treatment of atrial fibrillation

Introduction and objectivesPulmonary vein isolation (PVI) technique has become the cornerstone of atrial fibrillation (AF) catheter ablation. The objective of this study was to assess the efficacy and safety of extended antrum ablation based on electrophysiological substrate mapping plus PVI in AF patients who underwent cryoballoon ablation.MethodsIn this observational study, a total of 121 paroxysmal AF patients and 80 persistent AF patients who did not achieve the procedure endpoint after cryoballoon ablation received extra extended antrum ablation (EAA) based on electrophysiological substrate mapping via radiofrequency ablation (EAA group). As a control group (PVI group), among paroxysmal AF and persistent AF patients, we conducted a propensity score-matched cohort, in whom only PVI was completed.ResultsThe average follow-up time was 15.27±7.34 months. Compared with PVI group, paroxysmal AF patients in the EAA group had a significantly higher rate of AF-free survival (90.1% vs. 80.2%, p=0.027) and AF, atrial flutter, or atrial tachycardia (AFLAT) -free rate survival (89.3% vs. 79.3%, p=0.031). Persistent AF patients in the EAA group also had a significantly higher rate of AF-free survival (90.0% vs. 75.0%, p=0.016) and AFLAT-free survival (88.8% vs. 75.0%, p=0.029) than PVI group. Complication rates did not significantly differ between both groups, in either paroxysmal AF or persistent AF patients.ConclusionOur findings demonstrate that extra extended antrum ablation based on electrophysiological substrate mapping is effective and safe. Moreover, the strategy can improve the outcome of AF cryoablation.     

Incidence, location, and cause of recovery of electrical connections between the pulmonary veins and the left atrium after pulmonary vein isolation.

AIMS: The aim of this study was to reveal the incidence, location, and cause of recovery of the electrical connections (ECs) between the left atrium and the pulmonary veins (PVs) after the segmental ostial PV isolation (PVI). METHODS AND RESULTS: Pulmonary vein mapping and successful PVI were performed using a computerized three-dimensional mapping system (QMS2trade mark) with a basket catheter in 167 PVs in 53 consecutive patients with atrial fibrillation (AF). In 14 patients with recurrent AF after PVI, the same PV mapping and isolation as in the first procedure were performed, and the PV potential maps constructed by QMS2 in two different procedures were compared. Forty-nine recovered ECs were observed in 27 PVs, and all were eliminated by a few local radiofrequency (RF) applications. Thirty-four (69%) of those ECs recovered at the edge of original ECs, and another 15 (31%) recovered at the mid-portion of the continuous broad original ECs. CONCLUSION: Electrical connection recovery occurred most commonly at the edges of original ECs and occasionally at the mid-portion of continuous broad original ECs after PVI probably due to tissue oedema neighbouring the segmental RF lesions. Further RF lesions at the edge of original ECs and linear ablation to the continuous broad ECs may help reduce AF recurrence.     

Ablation von paroxysmalem Vorhofflimmern

The gold standard in ablation of paroxysmal atrial fibrillation (PAF) is radiofrequency (RF) based point by point pulmonary vein isolation (PVI). In the majority of patients with PAF (80?%) PVI can restore stable SR even during long-term follow-up of up to 5 years. However multiple procedures are often required. Cryo-balloon based PVI is an established technique. Safety and efficacy are comparable to RF ablation. Due to the high success rates in patients with PAF and the progression rate to persistent atrial fibrillation (AF) an early intervention is recommended as implemented in the latest guidelines for AF treatment.     

Intermediate term outcome after electrogram guided segmental ostial pulmonary vein isolation using an 8 mm tip catheter for paroxysmal atrial fibrillation

IntroductionPulmonary vein isolation (PVI) is the most widely used procedure for ablation in patients with paroxysmal atrial fibrillation (AF). Not withstanding recent advancements in this field, including sophisticated three-dimensional (3D) based imaging and advanced ablation catheters with contact force technology, many patients and healthcare systems in developing countries will not afford such an expensive therapeutic procedure. There are no data from India analyzing the efficacy of PVI for PAF using conventional mapping and ablation. In this article, we have summarized the intermediate term outcome following PVI in patients with PAF using electrogram-based mapping and a 8 mm tip ablation catheter.MethodA total of 42 consecutive patients who underwent PVI for symptomatic PAF not controlled with at least one antiarrhythmic drug were studied in a tertiary care institute from March 2011 to June 2018. Patients with rheumatic AF were excluded. The pulmonary vein (PV) anatomy was assessed by pulmonary angiography during the ablation procedure. Using conventional electrophysiologic mapping, a variable curve Lasso catheter placed in the PVs was used to guide the earliest site of breakthrough. The segmental ostial PVI was performed using a 8 mm tip radiofrequency (RF) ablation catheter. Elimination of all PV ostial potentials and complete entrance block into the PV were considered indicative of complete electrical isolation. Follow-up visits were scheduled at one, three, and six months after the procedure, and every six months thereafter. History, symptom review, clinical examination, and 12-lead ECG were performed at each follow-up.ResultsAt pre-discharge, 34 patients (81%) were in sinus rhythm, while eight patients (19%) continued to have atrial fibrillation. The age of the study population was 51.5 ± 11.7 yrs. The mean follow-up duration was 44 ± 21 months (range 6–84 months). The number of PVs isolated included one (five patients, 11.9%), two (20 patients, 47.6%), three (12 patients, 28.6%), and four (five patients, 11.9%). In 42 patients, a total of 101 PVs were isolated. The right superior PV (RSPV) was isolated in 37 patients, the left superior PV (LSPV) was isolated in 39 patients, the left inferior PV (LIPV) was isolated in 14 patients, and the right inferior PV (RIPV) was isolated in six patients. The procedure duration was 125 ± 29 min and the fluoroscopy time was 47 ± 13 min. The number of patients who remained in sinus rhythm at 1, 6, 12, and 24 months were 34 (81%), 32 (76%), 30 (71%), and 26 (62%), respectively. Two patients of these underwent repeat PVI, which was successful, and they had freedom from AF episodes. Complications were rare. One patient had a minor pericardial effusion, and one patient had transient sinus pauses, which were conservatively managed.ConclusionConventional RF ablation using PV potential-based mapping and ablation with 8 mm tip catheters is safe for patients with PAF. The intermediate term outcome is satisfactory and cost-effective in our setting with limited resources.     

Preliminary results of a limited thoracotomy: new approach to treat atrial fibrillation

Objective: To determine efficacy of a new procedure combining epicardial bipolar radiofrequency (RF) pulmonary vein (PV) antrum isolation and ganglionated plexus (GP) ablation for treatment of atrial fibrillation (AF).
Background: PV antrum electrical isolation and GP ablation have each been associated with elimination of AF. Both of these can be performed epicardially in a single combined surgical procedure, which may have advantages over endocardial ablation.
Methods and Results: Twenty-one subjects entered a prospective evaluation of limited thoracotomy epicardial bipolar PV antrum isolation, verified by PV recordings, with GP ablation, guided by GP mapping. Procedural success was defined as freedom from AF and antiarrhythmic agents during 1 year of follow-up, including evaluation by prolonged continuous monitoring capable of detecting asymptomatic arrhythmias. All subjects had recordable PV potentials and GP activity prior to ablation. Circumferential epicardial bipolar RF eliminated PV potentials in 18 of 20 right and 14 of 20 left PV antra. This concurrently eliminated 79% of GP activity (125 of 159 active sites); nearly all remaining GP activity could then be eliminated using epicardial bipolar RF forceps. Fifteen of 20 (75%) subjects overall, and 14 of 16 (87.5%) subjects with paroxysmal or persistent AF had a successful procedure.
Conclusion: Limited thoracotomy epicardial bipolar RF antrum isolation, verified by PV recordings, with GP ablation, guided by GP mapping, is effective treatment for AF and should be considered in patients with paroxysmal or persistent AF.     

Incidence of silent cerebral thromboembolic lesions after atrial fibrillation ablation may change according to technology used: comparison of irrigated radiofrequency, multipolar nonirrigated catheter and cryoballoon

AF Ablation Technologies and Silent Cerebral Ischemic Lesions. Introduction: Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies. Methods and Results: One hundred and eight patients (67% men; age 56 ± 9 years) with PAF were enrolled in a consecutive manner to undergo PVI performed with irrigated radiofrequency (RF) catheter (Group 1, 36 patients), multielectrode catheter (PVAC) associated with duty‐cycled RF generator (Group 2, 36 patients) and cryoballoon (Group 3, 36 patients). The protocol included a cerebral magnetic resonance imaging before and after the procedure. After PVI, the following patients showed new silent cerebral ischemic lesions at postprocedural cerebral MRI: 3 patients in Group 1 (8.3%), 14 patients in Group 2 (38.9%), 2 patients in Group 3 (5.6%). PVAC related to higher incidence of silent cerebral ischemic events compared to irrigated RF (P = 0.002) and cryoballoon (P = 0.001), whereas no statistical differences were found between irrigated RF catheter and cryoballoon groups (8.3% vs 5.6%, P = 0.5). At the multivariate analysis, the only independent predictor of new ischemic asymptomatic cerebral lesions after PVI was ablation performed with PVAC (OR 1.48 95% CI 1.19–1.62, P < 0.001). Conclusion: The incidence of silent cerebral lesions after PVI is different depending on technologies used: PVAC increases the risk of 1.48 times compared to irrigated RF and cryoballoon ablation. (J Cardiovasc Electrophysiol, Vol. 22, pp. 961‐968, September 2011)     

Impact of age on the outcome of pulmonary vein isolation for atrial fibrillation using circular mapping technique and cooled-tip ablation catheter:

INTRODUCTION: A retrospective analysis was performed to define the impact of age on the outcomes and complications in patients undergoing pulmonary vein isolation (PVI). PVI is an evolving technique for the management of atrial fibrillation (AF). The impact of age on the risks, outcomes, and complications of PVI has not been well defined. METHODS AND RESULTS: A total of 323 patients (259 men and 64 women; age 18-79 years) underwent PVI for treatment of drug-refractory symptomatic AF. An ostial isolation of the pulmonary veins was done using a cooled-tip ablation catheter guided by circular mapping. The patients were divided into three groups based on age (group I: <50 years, group II: 51-60 years, group III: >60 years) and the results were compared. There were 106 patients in group I, 114 patients in group II, and 103 patients in group III (mean age 41.3 +/- 7.8 years, 55.4 +/- 2.75 years, and 66.6 +/- 4.18 years, respectively) who underwent PVI for paroxysmal (53.8%), persistent (10.8%), or permanent (35.3%) AF. Baseline characteristics were similar except for a higher prevalence of hypertension and/or structural heart disease in groups II and III (58% and 63% vs 33% in group I, respectively). The procedural variables were similar in all age groups. The overall risk of complications was similar in the three groups, except that the risk of stroke was significantly higher in patients >60 years of age (3% vs 0%; P < 0.05). The recurrence rates of AF were similar in the three age groups (15.1%, 16.7%, and 18.4%, respectively; P > 0.05). The risk of severe pulmonary vein stenosis (1.8%, 2.6%, and 0.9%, respectively) was low and did not vary with age. CONCLUSION: PVI is a safe and effective treatment for patients with drug-refractory symptomatic AF, and its benefits extend to all age groups. The risk of procedural complications, especially thromboembolic events, appears to be higher in the elderly age group. This observation needs to be considered while assessing potential candidates for the procedure.     

A comparison of open irrigated and non-irrigated tip catheter ablation for pulmonary vein isolation.

AIMS: The relative efficacy and safety of open irrigated tip catheters compared with conventional non-irrigated catheters for pulmonary vein isolation (PVI) is unknown. METHODS: Forty-eight patients undergoing PVI using an open irrigated tip ablation catheter (Group 1) were compared with a group of 31 historical controls (Group 2). The control group underwent similar procedures using a standard, 4 mm tip, temperature controlled ablation catheter. Electrical mapping with a circular catheter was used to guide segmental radiofrequency ablation at the vein ostia. RESULTS: At follow-up (3.5+/-3.5 months) after a single procedure 35/48 (73%) patients in Group 1 and 14/31 (45%) in Group 2 were in sinus rhythm (p=0.03). Antiarrhythmic drug use was lower among those in Group 1 maintained in sinus rhythm (9/35 (26%) vs 8/14 (57%), p=0.002). Recurrent atrial fibrillation was more common in Group 2 (28/31 (90%) vs 28/48 (58%) p=0.004). Serious complications were uncommon in both groups. CONCLUSIONS: Compared with an historical control group, pulmonary vein isolation using open irrigated tip catheters was superior to ablation with conventional 4 mm tip catheters. Patients undergoing ablation with an irrigated tip catheter were less likely to experience symptomatic recurrences of atrial fibrillation or require further therapy for post-procedural arrhythmias.     

Impact of Systematic Isolation of Superior Vena Cava in Addition to Pulmonary Vein Antrum Isolation on the Outcome of Paroxysmal, Persistent, and Permanent Atrial Fibrillation Ablation: Results from a Randomized Study

Impact of the Systematic Isolation of the Superior Vena Cava.   Background: Pulmonary veins (PVs) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation (AF). However, additional non-PV triggers, arising from different areas, have been reported as well. One of the most common non-PV sites described is the superior vena cava.
Aims: The purpose of the study was to investigate the impact resulting from the systematic isolation of the superior vena cava (SVCI) in addition to pulmonary vein antrum isolation (PVAI) on the outcome of paroxysmal, persistent, and permanent AF ablation.
Methods: A total of 320 consecutive patients who had been referred to our center in order to undergo a first attempt of AF ablation were randomized into 2 groups. Group I (160 patients) underwent PVAI only; Group II (160 patients) underwent PVAI and SVCI.
Results: AF was paroxysmal in 134 (46%), persistent in 75 (23%), and permanent in 111 (31%) of said patients. SVCI was performed on 134 of the 160 patients (84%) in Group II. SVC isolation was not performed on the remaining 26 patients either because of phrenic nerve capture or the lack of SVC potentials. Comparison of the outcome data between the 2 groups, after a follow-up of 12 months, revealed a significant difference in total procedural success solely with patients manifesting paroxysmal atrial fibrillation (56/73 [77%] Group I vs. 55/61 [90%] Group II; P = 0.04; OR 2.78).
Conclusions: In our study, the strategy of the empiric SVCI in addition to PVAI has improved the outcome of AF ablation solely in patients manifesting paroxysmal AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1–5, January 2010)     

Cryoballoon ablation versus radiofrequency ablation for atrial fibrillation

Catheter ablation (CA) provides the most effective treatment option for patients suffering from symptomatic atrial fibrillation (AF). The procedural cornerstone of all ablation strategies and for all entities of AF is the electrical isolation of the pulmonary veins (PV). CA with the use of radiofrequency (RF) in conjunction with a 3-dimensional electroanatomical mapping system is the most established ablation approach, but it demands a long learning curve and recurrences of AF are commonly the result of recovered PV conduction. As a consequence, novel ablation systems such as the Cryoballoon (CB) have been evolved aiming at facilitation and increased efficacy of pulmonary vein isolation (PVI). CB ablation is characterized by a short learning curve as well as short procedure times and demonstrated non-inferiority with regard to safety and efficacy when being directly compared to RF ablation for treatment of paroxysmal AF. However, RF ablation is first choice for treatment of persistent AF, in particular when expanded ablation strategies beyond PVI are intended in order to improve clinical outcomes.     

Cryoballoon Versus Radiofrequency for Pulmonary Vein Re‐Isolation After a Failed Initial Ablation Procedure in Patients with Paroxysmal Atrial Fibrillation

Cryoballoon versus Radiofrequency Ablation . Aim: Catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with an important risk of early and late recurrence, necessitating repeat ablation procedures. The aim of this prospective randomized patient‐blind study was to compare the efficacy and safety of cryoballoon (Cryo) versus radiofrequency (RF) ablation of PAF after failed initial RF ablation procedure. Methods: Patients with a history of symptomatic PAF after a previous failed first RF ablation procedure were eligible for this study. Patients were randomized to Cryo or RF redo ablation. The primary endpoint of the study was recurrence of atrial tachyarrhythmia, including AF and left atrial flutter/tachycardia, after a second ablation procedure at 1 year of follow‐up. All patients were implanted with a cardiac monitor (Reveal XT, Medtronic) to continuously track the cardiac rhythm. Patients with an AF burden (AF%) ≤ 0.5% were considered AF‐free (Responders), while those with an AF% > 0.5% were classified as patients with AF recurrences (non‐Responders). Results: Eighty patients with AF recurrences after a first RF pulmonary vein isolation (PVI) were randomized to Cryo (N = 40) or to RF (N = 40). Electrical potentials were recorded in 77 mapped PVs (1.9 ± 0.8 per patient) in Cryo Group and 72 PVs (1.7 ± 0.8 per patient) in RF Group (P = 0.62), all of which were targeted. In Cryo group, 68 (88%) of the 77 PVs were re‐isolated using only Cryo technique; the remaining 9 PVs were re‐isolated using RF. In RF group, all 72 PVs were successfully re‐isolated (P = 0.003 vs Cryo). By intention‐to‐treat, 23 (58%) RF patients were AF‐free vs 17 (43%) Cryo patients on no antiarrhythmic drugs at 1 year (P = 0.06). Three patients had temporary phrenic nerve paralysis in the Cryo group; the RF group had no complications. Of the 29 patients who had only Cryo PVI without any RF ablation, 11 (38%) were AF‐free vs 20 (59%) of the 34 patients who had RF only (P = 0.021). Conclusion: When patients require a redo pulmonary vein isolation ablation procedure for recurrent PAF, RF appears to be the preferred energy source relative to Cryo. (J Cardiovasc Electrophysiol, Vol. 24, pp. 274‐279, March 2013)     

Cerebral microembolization during atrial fibrillation ablation: Comparison of different single-shot ablation techniques

Background

Clinically silent cerebral ischemia (SCI) detected by diffusion-weighted MRI has been reported in 5–40% of patients undergoing pulmonary vein isolation (PVI). Although initial reports suggested a high rate of SCI with phased radiofrequency (RF) ablation on use of the pulmonary vein ablation catheter (PVAC), the incidence was subsequently markedly reduced in consequence of procedural modifications in recent studies.We analyzed cerebral microembolization as assessed with transcranial Doppler during phased RF ablation and with two other single-shot AF ablation technologies: the cryoballoon (CB) and the nMARQ™ multipolar irrigated RF ablation system.

Methods and results

A total of 89 patients (mean age: 57, SD: 12 years; 62 males) with paroxysmal or persistent AF underwent PVI. Phased RF was used according to the initial protocol in 7 patients (PVAC Group I), with procedural modifications and a newer (14.4) version of the RF generator in 37 patients (PVAC Group II) and with the most recent (version 15.1) generator in 18 patients (PVAC Group III). Ablation was performed with the CB in 13 and with the nMARQ system in 14 patients.The number of microemboli (mean + (SD)) detected in the middle cerebral arteries was 2703 (918) in PVAC Group I, 1087 (542) in PVAC Group II, 719 (469) in PVAC Group III, 1057 (784) with CB and 2166 (1047) with nMARQ (p < 0.01).

Conclusion

Significant decreases in MES counts were observed thanks to the procedural modifications and newer RF generator with phased RF. High MES counts comparable to those with the initial phased RF resulted from the use of nMARQ.     

阵发性心房颤动患者肺静脉前庭电生理现象及分析

目的采用EnSite/NavX系统指导下,结合单Lasso进行环肺静脉电隔离术治疗阵发性心房颤动(简称房颤),分析消融过程中肺静脉前庭电生理现象。方法入选2004年10月~2005年12月症状性阵发性房颤患者143例,男85例、女58例,年龄60.7±10.3(35~80)岁,房颤病程5.5±6.7年(21天~50年),左房内径36.9±6.4(24~54)mm。在EnSite-NavX系统引导下行环肺静脉消融达到肺静脉电隔离。结果143例完成环肺静脉隔离术,手术时间157±30(90~240)min,放射线时间25.8±8.8(9.8~60.1)min。环单侧左、右肺静脉前庭消融电隔离率分别为81.2%、78.3%,其余病例结合节段性消融(SOA)达到肺静脉电隔离。房颤终止的比例为69.7%(23/33例),第一次消融63.6%(91/143)可记录到肺静脉内自发电位,2.1%(3/143)可记录到肺静脉内快速的自主节律,而体表心电图为稳定的窦性心律。房颤复发患者第二次消融时,所有21例均有肺静脉电位(PVP)恢复,其中第一次消融时结合SOA达到肺静脉隔离的患者:57.1%左侧PVP恢复,55.6%右侧PVP恢复。第二次消融时,85.7%(18/21)例存在肺静脉内自发电位。术后房性心动过速/心房扑动15例(10.5%),12例再次行射频消融治疗,11例消融成功。术后随访10.7±4.9(4~18)个月,包括第二次消融术后患者在内,共90.2%(129/143)在无抗心律失常药物治疗下无房颤发作。心包积液2例,Ensite/NavX电极贴片故障1例。结论心房-肺静脉传导存在优势传导径路,且传导方式并非“全或无”;结合SOA的消融方法复发率较高;多数患者肺静脉隔离后可记录到自发肺静脉电位,复发患者的肺静脉通常具有较高的兴奋性。     

The role of left atrial muscular bundles in catheter ablation of atrial fibrillation.

OBJECTIVES: We sought to investigate the imaging of the left atrial (LA) muscular bundle and the relationship between the bundle and inducibility of tachyarrhythmia after pulmonary vein isolation (PVI). BACKGROUND: Noninducibility is used as a clinical end point of atrial substrate ablation after PVI. However, little is known about the role of the LA muscular bundles in tachyarrhythmia after PVI. METHODS: Forty-three consecutive patients with paroxysmal atrial fibrillation who underwent catheter ablation were included. Bi-atrial isochronal mapping was performed with the NavX system (St. Jude Medical Inc., St. Paul, Minnesota) during sinus rhythm. After 4 PVI, inducible organized LA flutter with or without transforming to atrial fibrillation (AF) (LA flutter/AF) was ablated with additional lines at the roof and/or mitral isthmus. RESULTS: The existence of bilateral muscular bundles was an independent predictor of LA flutter/AF after PVI (p = 0.02). Patients with LA flutter/AF after PVI had a greater index of the double potentials (5.4 +/- 3.4% vs. 2.8 +/- 1.8%, p = 0.006) and interpotential interval (33 +/- 5 ms vs. 29 +/- 4 ms, p = 0.02) than without LA flutter/AF. The muscular bundles were identified in 28% patients using 16-slice multidetector computed tomography, which were identical to the isochrone map. Patients with noninducible LA flutter/AF after PVI plus the additional linear ablation had a lower recurrence rate as compared with the patients without it (19% vs. 75%, p = 0.02). CONCLUSIONS: Left atrial muscular bundles may provide a conduction block line and barrier, which is important for the formation of LA flutter/AF after PVI. The noninducibility of LA flutter/AF achieved after additional linear ablation may contribute to a better outcome in RF ablation of paroxysmal atrial fibrillation.     

Randomized comparison of bipolar versus unipolar plus bipolar recordings during segmental ostial ablation of pulmonary veins

INTRODUCTION: Segmental ostial ablation to isolate pulmonary veins is guided by pulmonary vein potentials. The aim of this prospective randomized study was to compare the utility of unipolar plus bipolar electrograms versus only bipolar electrograms as a guide for segmental ablation to isolate the pulmonary veins in patients with atrial fibrillation. METHODS AND RESULTS: Isolation of the left superior, right superior, and left inferior pulmonary veins was attempted in 44 patients (35 men and 9 women; mean age 54 +/- 10 years) with paroxysmal atrial fibrillation. A decapolar Lasso catheter was positioned in the pulmonary veins, near the ostium, and a conventional ablation catheter was used for segmental ablation aimed at elimination of all pulmonary vein potentials. One hundred fourteen pulmonary veins were randomly assigned for ostial ablation guided by either bipolar or unipolar plus bipolar recordings. Electrical isolation was achieved in 51 (96%) of 53 pulmonary veins randomized to the bipolar approach, and 57 (93%) of 61 pulmonary veins randomized to the unipolar plus bipolar approach (P = 0.7). In the unipolar plus bipolar group, the total duration of radiofrequency energy needed to achieve isolation, 5.5 +/- 2.8 minutes/vein, was significant shorter than in the bipolar group, 7.6 +/- 4.1 minutes/vein (P < 0.01). Mean procedure and fluoroscopy durations per vein were 19% to 28% shorter in the unipolar plus bipolar group. CONCLUSION: Segmental ostial ablation to isolate the pulmonary veins can be achieved more efficiently and with less radiofrequency energy when guided by both unipolar and bipolar recordings than by bipolar recordings alone.     

Reduction of AF recurrence after pulmonary vein isolation by eliminating ATP-induced transient venous re-conduction

Background: Recent evidence has suggested that the transient re-conduction of the isolated pulmonary vein (PV) induced by the intravenous injection of adenosine (dormant PV conduction) might predict the incidence of subsequent venous reconnection after the procedure, which is the main cause of the atrial fibrillation (AF) recurrence after PV isolation (PVI). We tested the hypothesis that the elimination of these dormant PV conductions by additional radiofrequency (RF) applications can improve the efficacy of the PVI.
Methods and Results: One hundred forty-eight patients (124 males; mean age 53 ± 9 years) with drug-refractory AF underwent the PVI procedure. The standard PVI was performed in 94 patients (Group A), whereas the elimination of adenosine triphosphate (ATP)-induced dormant conduction using additional RF energy was performed in addition to the standard PVI in other 54 patients (Group B). Dormant conduction was observed in 56% of the patients (30/54) in Group B and 95% of these transient re-conductions were successfully eliminated by additional RF applications (mean: 1.5 ± 1.0 times). During the mean follow-up period of 20 months, recurrences of AF after the procedures were observed significantly less frequently in Group B (20%) than in Group A (40%) (P < 0.05).
Conclusion: The use of additional RF applications to eliminate transient PV reconnection induced by ATP injection led to a reduction of AF recurrence after PVI, most likely due to the minimization of the subsequent PV reconnection.     

Successful radiofrequency catheter ablation of recurrent atrial fibrillation due to left inferior pulmonary vein tachycardia

This report illustrates the case of a young lady evaluated for drug-refractory symptomatic paroxysmal atrial fibrillation. Successful isolation of left inferior pulmonary vein was achieved by segmental ostial ablation and circumferential Lasso mapping catheter. Patient is now free of symptoms and is off all anti-arrhythmic drugs.     

Hypertension and hypertensive heart disease are associated with increased ostial pulmonary vein diameter

INTRODUCTION: Atrial fibrillation (AF) is associated with increased ostial pulmonary vein (PV) diameter and commonly with hypertension. We sought to investigate ostial PV anatomy in patients with and without AF with the goal of characterizing the relationship to hypertension and cardiovascular disease. METHODS AND RESULTS: Ostial PV diameter was assessed by preprocedural spiral computed tomography in 100 AF patients undergoing a PV isolation procedure and in 24 age- and sex-matched non-AF control patients. Ostial diameter of 392 PVs in 100 AF patients was increased compared to 106 PVs in 24 non-AF controls (1.50 +/- 0.31 vs 1.20 +/- 0.31 cm, P <0.001) and diameters of individual PVs were uniformly affected (r=0.45-0.62, P <0.001). Left atrial dilation was associated with a larger PV diameter (1.56 +/- 0.32 vs 1.44 +/- 0.29 cm, P <0.01). PV diameter in AF patients with hypertension (1.55 +/- 0.32 cm), particularly if associated with left ventricular hypertrophy (1.66 +/- 0.37 cm), was larger compared to AF patients without hypertension (1.43 +/- 0.26 cm, P <0.01). PV diameter in control patients with hypertension (n=14) was larger than in those without hypertension (n=10, P <0.01). Patients with persistent AF had larger PV diameters (1.61 +/- 0.34 cm) than patients with paroxysmal AF (1.47 +/- 0.30 cm, P <0.01). Male gender (P <0.01), history of hypertension (P <0.01), and persistent AF (P <0.05) were identified as independent cofactors of increased ostial PV diameter. Conclusion: PV dilation affects all PVs uniformly in AF patients. Hypertension and hypertensive heart disease in patients with and without AF are associated with PV dilation, supporting theories that impaired left ventricular diastolic function is associated with a stretch-induced PV arrhythmia mechanism.     

Adjunct ablation strategies for persistent atrial fibrillation—beyond pulmonary vein isolation

Atrial fibrillation (AF) is the most common sustained arrhythmia. Recent guidelines recommend pulmonary vein isolation (PVI) as the main procedural endpoint to control recurrent AF in symptomatic patients resistant to antiarrhythmic drugs. The efficacy of such procedure is higher in paroxysmal AF while is still unsatisfactory in persistent and long-standing persistent AF. This review will summarize the state-of-the-art of AF ablation techniques in patients with persistent AF, discussing the evidence underlying different approaches with a particular focus on adjunctive ablation strategies beyond PVI including linear ablation, ablation of complex fractionated atrial electrograms (CFAE), ablation of ganglionated plexi, dominant frequency, rotors and other anatomical sites frequently involved in AF triggers.     

Predictors of early recurrence and delayed cure after segmental pulmonary vein isolation for paroxysmal atrial fibrillation without structural heart disease

Background Early recurrence of atrial fibrillation (ERAF) and delayed cure are commonly observed after atrial fibrillation (AF) ablation. The purpose of this study was to determine the predictors of ERAF and delayed cure after a single pulmonary vein isolation (PVI) performed in paroxysmal AF patients without structural heart disease.Methods and results In 108 consecutive patients (93 men, 15 women; mean age 51 ± 8 years) with paroxysmal AF and no structural heart disease, segmental PVI guided by a Lasso catheter was performed. Forty-one percent (44/108) AF patients had ERAF after a single PVI. Univariate analysis revealed that left atrial diameter (p = 0.004), age (p = 0.024) and P-wave dispersion (p = 0.045) were significantly related to ERAF. Logistic regression analysis revealed that left atrial enlargement was the only independent predictor of ERAF (odds ratio [OR] 1.17; 95% confidence interval [CI] 1.04–1.30, p = 0.006). Delayed cure occurred in 32% (14/44) patients with ERAF. P-wave dispersion (p = 0.001), left atrial diameter (p = 0.008) were significantly related to delayed cure. P-wave dispersion was the only independent predictive factor of delayed cure (OR 0.91; 95% CI 0.85–0.97, p = 0.004).Conclusions Elderly patients with left atrial enlargement and a high dispersion of P wave are susceptible to ERAF after a single PVI. Left atrial enlargement is the only independent predictor of ERAF. Among patients with ERAF, those with less P-wave dispersion and less left atrial diameter have a higher probability of delayed cure. P-wave dispersion can independently predict delayed cure.This study was supported by National Natural Science Foundation of China. (NSFC No.30470704). There is not any potential conflict of interest.