Early Detection of Pulmonary Vein Reconnection After Isolation in Patients With Paroxysmal Atrial Fibrillation: A Comparison of ATP‐Induction and Reassessment at 30 Minutes Postisolation

Introduction: Catheter ablation for paroxysmal AF (PAF) is limited by an unacceptable recurrence rate, mainly due to pulmonary vein (PV) reconnection. Strategies to minimize reconnection include adenosine infusion and also a waiting period of 30 minutes after PV isolation. The aim of the present study was to assess whether these two strategies revealed the same conduction gap. Methods and Results: In total, 88 consecutive patients (54 males, mean age of 60 years) with drug refractory PAF underwent circumferential PV isolation (CPVI). After isolation of ipsilateral PVs, with entry and exit block checked using a circular mapping catheter, 20 mg ATP was injected during isoproterenol infusion to reveal dormant conduction gap(s). Unless the reconnection revealed by ATP persisted, PVs were further remapped with the circular mapping catheter at 30 minutes postisolation. Totally, PV reconnection was observed in 56 (64%) patients. 24.3% veins (80/329) were found reconnected. Reassessment at 30 minutes postablation was more efficient as compared to ATP induction (19.8% vs 14.6% for ATP). The agreement between these 2 methods is moderate (kappa value = 0.50). In veins that transiently reconnected after ATP administration and later observed at 30 minutes postablation, 94% (17 of 19) of them were found being reconnected with the same gap. Conclusion: Acute PV reconnection is common, occurring in 64% of patients, as detected by adenosine infusion and waiting time. Each shows a unique quality as compared to one another. The combined use of these 2 methods may reduce the AF recurrence rate after CPVI.     

Pulmonary vein isolation combined with superior vena cava isolation for atrial fibrillation ablation: a prospective randomized study

Aims: Circumferential pulmonary vein isolation (CPVI) is an establishedstrategy for atrial fibrillation (AF) ablation. Superior venacava (SVC), by harbouring the majority of non-pulmonary vein(PV) foci, is the most common non-PV origin for AF. However,it is unknown whether CPVI combined with SVC isolation (SVCI)could improve clinical results and whether SVCI is technicallysafe and feasible. Methods and results: A total of 106 cases (58 males, average age 66.0 ± 8.8years) with paroxysmal AF were included for ablation. They wereallocated randomly to two groups: CPVI group (n = 54) and CPVI+ SVCI group (n = 52). All cases underwent the procedure successfully.Pulmonary vein isolation was achieved in all cases. The proceduraltime and fluoroscopic time were comparable between the two groups.The mean ablation time for SVC was 7.8 ± 2.7 min. Superiorvena cava isolation was obtained in 50/52 cases. In the remainingtwo cases, SVCI was not achieved because of obviating diaphragmaticnerve injury. During a mean follow-up of 4 ± 2 months,12 (22.2%) cases in the CPVI group and 10 (19.2%) cases in theCPVI + SVCI group had atrial tachyarrhythmias (ATa) recurrence(P = 0.70). Nine of 12 cases in the CPVI group and 8/10 casesin the CPVI + SVCI group underwent reablation (P = 0.86), andPV reconnection occurred in 7/9 cases in the CPVI group andin 8/8 cases in the CPVI + SVCI group. All PV reconnection wasreisolated by gaps ablation. There was no SVC reconnection inthe CPVI + SVCI group. In two cases without PV reconnectionfrom the CPVI group, SVC-originated short run of atrial tachycardiawas identified and eliminated by the SVCI. At the end of 12months of follow-up, 50 cases (92.6%) in the CPVI group and49 (94.2%) in the CPVI + SVC group were free of ATa recurrence(P = 0.73). Conclusion: In our series of paroxysmal AF patients, empirically addingSVCI to CPVI did not significantly reduce the AF recurrenceafter ablation. Superior vena cava isolation may be useful,however, in selected patients in whom the SVC is identifiedas a trigger for AF. However, because of the preliminary propertyof the study and its relatively small sample size, the impactof SVCI on clinical results should be evaluated in a large seriesof patients.     

Pulmonary Vein Contraction Before and After Radiofrequency Ablation for Atrial Fibrillation

Pulmonary Vein Contraction After Ablation. Introduction: Cardiovascular magnetic resonance imaging (cMRI) may provide a noninvasive method to test for pulmonary vein (PV) isolation after ablation for atrial fibrillation (AF) by detecting changes in PV contraction. Methods: PV contraction (the maximal percentage change in PV cross‐sectional area [CSA] during the cardiac cycle) measured 1 month before and 2 months after PV isolation was compared in 63 PVs from 16 patients with medically refractory AF. Repeat cMRI imaging and invasive catheter mapping was performed prior to repeat PV ablation in 50 PVs from 14 additional patients with recurrent AF. Contraction in PVs with sustained isolation after the initial ablation was compared to contraction in PVs with electrical reconnection to adjacent atrium. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff PV contraction value for prediction of PV‐atrial reconnection after ablation. The cutoff value was then prospectively tested in 40 PVs from 12 additional patients. Results: PV contraction decreased after AF ablation (22.4 ± 10% variation in CSA before ablation vs 10.1 ± 8% variation in CSA after ablation, P < 0.00001). PVs with sustained isolation on invasive mapping contracted less than PVs with electrical reconnection to adjacent atrium (13.7 ± 10.6% vs 21.4 ± 9.3%, P = 0.021). PV contraction produced a c‐index of 0.74 for prediction of PV‐atrial reconnection after ablation and >17% variation in PV CSA predicted reconnection with a sensitivity of 84.6% and specificity of 66.7%. Conclusion: PV contraction is reduced by ablation. PV contraction measurement may provide a noninvasive method to test for PV isolation after ablation procedures. (J Cardiovasc Electrophysiol, Vol. 22, pp. 169‐174, February 2011)     

Efficacy of repeat pulmonary vein isolation procedures in patients with recurrent atrial fibrillation

INTRODUCTION: Pulmonary vein (PV) isolation is effective in the treatment of most patients with atrial fibrillation (AF). Some advocate the addition of linear ablation techniques to improve efficacy; however, previous studies suggest recurrent PV conduction is responsible for AF recurrence. The aim of this study was to determine the effectiveness of repeat PV isolation in patients with recurrent AF after an initial ablation procedure and to determine if any patient characteristics predict failure of repeat PV isolation procedures. METHODS AND RESULTS: Seventy-four patients with two or more AF ablation procedures using selective PV isolation were included. PV isolation was guided with multielectrode ring catheter recordings, electroanatomic mapping, and intracardiac electrocardiography. Radiofrequency energy was delivered using a 4-mm-tip catheter (maximum 40 W, 52 degrees C); cooled-tip ablation was performed in 10 patients. Linear ablation was not performed. Antiarrhythmic drugs were continued for at least 6 weeks after ablation; AF episodes during this period were censored. Reconnection of one or more segments of previously ablated PVs was observed in 97% of patients; reconnected PVs served as the trigger for AF in 77%. Repeat PV isolation resulted in AF control (cure or 90% reduction in AF episodes) in 64 patients (86%) over a follow-up period of 9.1 +/- 6.7 months. "High-risk" characteristics such as left atrial enlargement, persistent AF, or mitral regurgitation did not predict failure of repeat PV isolation procedures. CONCLUSION: Recurrent AF following selective PV isolation is overwhelmingly associated with PV electrical reconnection. Repeat PV isolation without linear ablation provides effective treatment for recurrent AF in patients in whom an initial PV isolation procedure failed, independent of clinical characteristics.     

Ablation of perimitral flutter following catheter ablation of atrial fibrillation: impact on outcomes from a randomized study (PROPOSE)

MVI Block vs Trigger Ablation in PMFL . Introduction: Patients with previous ablation for atrial fibrillation (AF) may experience recurrence of perimitral flutter (PMFL). These arrhythmias are usually triggered from sources that may also induce AF. This study aims at determining whether ablation of triggers or completing mitral valve isthmus (MVI) block prevents more arrhythmia recurrences. Methods and Results: Sixty‐five patients with recurrent PMFL after initial ablation of long standing persistent AF were included in this study. Thirty‐two patients were randomized to MVI ablation only (Group 1) and 33 were randomized to cardioversion and repeat pulmonary vein (PV) isolation plus ablation of non‐PV triggers (Group 2). MVI bidirectional block was achieved in all but 1 patient from Group 1. In Group 2, reconnection of 17 PVs was detected in 14 patients (42%). With isoproterenol challenge, 44 non‐PV trigger sites were identified in 28 patients (85%, 1.57 sites per patient). At 18‐month follow‐up, 27 patients (84%) from Group 1 had recurrent atrial tachyarrhythmias, of whom 15 remained on antiarrhythmic drug (AAD); however, 28 patients from Group 2 (85%, P < 0.0001 vs Group 1) were free from arrhythmia off AAD. The ablation strategy used in Group 2 was associated with a lower risk of recurrence (hazard ratio = 0.10, 95% CI 0.04–0.28, P < 0.001) and an improved arrhythmia‐free survival (log rank P < 0.0001). Conclusion: In patients presenting with PMFL after ablation for longstanding persistent AF, MVI block had limited impact on arrhythmia recurrence. On the other hand, elimination of all PV and non‐PV triggers achieved higher freedom from atrial arrhythmias at follow‐up. (J Cardiovasc Electrophysiol, Vol. 23, pp. 137‐144, February 2012)     

Conduction recovery in patients with recurrent atrial fibrillation after pulmonary vein isolation using multi-electrode duty cycled radiofrequency ablation

Introduction

The pulmonary vein ablation catheter (PVAC) is designed for pulmonary vein isolation (PVI). Electrical reconnection of pulmonary veins is believed to result in AF recurrence. The purpose of this study was to establish the location and extent of PV reconnection after PVI with the PVAC catheter.

Methods and results

Eighty-two patients (79 % male, age 60?±?9 years) that underwent a redo procedure for recurrent AF after PVAC ablation were assessed for prevalence and location of reconnection. The number of reconnected PV’s was 0, 1, 2, 3, or 4 in 2 (2.4 %), 14 (17 %), 23 (28 %), 28 (34 %), and 15 (18 %) patients, respectively. Reconnection of left superior, left inferior, left common, right superior, and right inferior PV’s was found in 66, 63, 83, 57, and 67 %, respectively (p?=?0.48). In the left PV’s, reconnection was located significantly more anterior than posterior; LSPV anterior 32/70 vs posterior 13/70 (p?<?0.01), LIPV anterior 26/70 vs posterior 9/70 (p?<?0.01). In the right PV’s reconnection was distributed equally in all quadrants. Different modes of RF delivery during PVAC ablation (bipolar/unipolar 2:1 [n?=?35] vs. 4:1 [n?=?47]) yielded comparable rates of PV reconnection. During follow-up (median 296 days) no AF/AT was documented in 57 patients (70 %).

Conclusion

Almost all patients (98 %) with AF after PVAC ablation show reconnection of at least one PV. All PV’s are equally likely to show reconnection. In the left PV’s, reconnection was found more often anteriorly than posteriorly. During pulmonary vein isolation with the PVAC catheter, prevalent sites of reconnection deserve close attention to increase success.     

Comparison of Cooled-Tip Versus 4-mm-Tip Catheter in the Efficacy of Acute Ablative Tissue Injury During Circumferential Pulmonary Vein Isolation

Introduction: Although several studies have reported the benefits of cooled-tip ablation for circumferential pulmonary veins isolation (CPVI), the acute change of substrate property and acute PV reconnection have not been well demonstrated. The aim of this study was to compare the cooled-tip with regular 4-mm-tip catheter in acute substrate change after CPVI and long-term efficacy.
Methods and Results: One hundred and fifty-six patients (115 males, age 53 ± 12 years) who underwent CPVI for treatment of atrial fibrillation (AF) were included. Group A consisted of 52 patients with cooled-tip ablation, and group B consisted of 104 patients with 4-mm-tip catheter ablation. The bipolar voltage of circumferential lesions was obtained using a 3-dimensional (3D) mapping system (NavX) before and after CPVI. The electrical reconnections of 4 PVs were evaluated 30 minutes after CPVI using a circular catheter. Cooled-tip catheter caused more reduction of the electrical voltage in PV antrum, lower incidence of acute PV reconnection, inducibility of AF, and gap-related atrial tachyarrhythmia (AT). Less number of left atrial (LA) ablation line and ablation applications and less procedure time were found in cooled-tip group compared to 4-mm-tip group. No significant difference in the incidence of pain sensation and complication was observed between the 2 groups. At a 14-month follow-up, the recurrence rate in the cooled-tip group was lower than in the 4-mm group (13.5% vs 33.7%, P = 0.009).
Conclusion: Cooled-tip catheter has a superior long-term outcome than the 4-mm-tip catheter in CPVI, which may be associated with the efficacy of transmural block and electrical isolation in PV antrum.     

Catheter Ablation of Long‐Standing Persistent Atrial Fibrillation: A Lesson from Circumferential Pulmonary Vein Isolation

Catheter Ablation of Long‐Standing Persistent AF. Introduction: Circumferential pulmonary vein isolation (CPVI) is associated with a high success rate in patients with paroxysmal and persistent atrial fibrillation (AF). However, in patients with long‐standing persistent AF, the ideal ablation strategy still remains a matter of debate. Methods and Results: Two‐hundred and five patients underwent catheter ablation for long‐standing persistent AF defined as continuous AF of more than 1‐year duration. In a first step, all patients underwent CPVI. If direct‐current cardioversion failed following CPVI, ablation of complex fractionated atrial electrograms (CFAEs) was performed. The goal was conversion into sinus rhythm (SR) or, alternatively, atrial tachycardia (AT) with subsequent ablation. A total of 340 procedures were performed. CPVI alone was performed during 165 procedures in 124 of 205 (60.5%) patients. In the remaining 81 patients, additional CFAE ablation was performed in 45, left linear lesions for recurrent ATs in 44 and SVC isolation in 15 patients, respectively, resulting in inadvertent left atrial appendage isolation in 9 (4.4%) patients. After the initial ablation procedure, 67 of 199 patients remained in SR during a mean follow‐up of 19 ± 11 months. Six patients were lost to follow‐up. After a mean of 1.7 ± 0.8 procedures, 135 of 199 patients (67.8%) remained in SR. Eighty‐six patients (43.2%) remained in SR following CPVI performed as the sole ablative strategy. Conclusions: CPVI alone is sufficient to restore SR in 43.2% of patients with long‐standing persistent AF. Multiple procedures and additional ablation strategies with a significant risk of inadvertent left atrial appendage isolation are often required to maintain stable SR. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1085‐1093)     

The significance of pulmonary veins isolation radiofrequency time and the evolution of left atrium volume on a twelve-year observational follow-up of paroxysmal atrial fibrillation patients

AimsPulmonary vein isolation (PVI) is the treatment of choice of paroxysmal atrial fibrillation (PAF). However, radiofrequency delivery at extra-PV sites may be additionally required. We compared clinical and procedural characteristics of patients undergoing PVI alone versus adjunctive extra-PV substrate modification, at first procedure and repeat procedures for AF recurrence.Methods587 patients with PAF undergoing radiofrequency (RF) ablation were retrospectively included. Extra-PV ablation was performed in case of sustained AF despite PVI, or at re-do procedures without PV conduction recovery. Demographic, clinical and electrophysiological predictors of survival without re-intervention were analysed in patients’ groups having undergone one (G1), two (G2) or three or more procedures (G3).ResultsAt baseline procedure, PV RF ablation time was shorter in G1 compared to G2/G3 whereas extra-PV RF ablation time was greater in G3 compared to G1. The proportion of patients requiring PV re-isolation decreased with repeat procedures. Smaller LA before procedure 1 (p1) or p2 was associated with PV reconnection at p2. Conversely larger LA before p1 was associated with extra-PV substrate modification at p2. Late re-do procedure timing (>1yr) was associated with increasing LA volume. Only longer PV and total RF time predicted poorer survival free from AF without re-intervention.ConclusionLonger PV RF time predicted requirement for re-ablation during follow-up. Smaller LA size predicted an increased probability of PV reconnection and decreased extra-PV substrate modification at p2. LA size decreased in patients undergoing early re-intervention, whereas it increased in patients undergoing re-intervention later on suggesting ongoing remodelling or progression.     

Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation without Additional Substrate Modification for Treating Longstanding Persistent Atrial Fibrillation

PV Ablation for Persistent Atrial Fibrillation. Introduction: Effectiveness of antral pulmonary vein isolation (PVAI) and ablation of non‐PV triggers (non‐PVTA) in controlling longstanding persistent atrial fibrillation (AF) has not been reported. We sought to describe clinical outcomes with this ablation strategy in patients (pts) followed for at least 1 year. Methods: Two hundred pts underwent PVAI for longstanding persistent AF and were followed for recurrence. Thirty‐three pts with <1‐year follow‐up and 37 pts with additional RF atrial ablation were excluded, leaving 130 pts for analysis. Results: All 130 pts (108 men, mean LA 4.7 ± 0.6 cm, mean AF duration of 38 ± 44 months) underwent PVAI with entrance/exit block. In addition, 24 pts (15 pts during the initial procedure and 9 additional pts at repeat ablations) had 40 non‐PVTA, including 3 with AVNRT. During follow‐up, atrial flutter (AFL) was noted in 7 (5%) pts. The AF‐free survival after single procedure without antiarrhythmic drugs (AAD) was 38%. Repeat AF or AFL ablation was performed in 37 pts (28%) with PV reconnection uniformly identified (3.7 ± 0.5 veins/pt). During mean follow‐up of 41.1 ± 23.8 months (range 12–103 months), 85/130 pts (65%) were in sinus rhythm with 65 pts (50%) off AAD, 20 pts (15%) on AAD. Additionally, 9 pts (7%) have had rare episodes of AF such that 72% of pts have had good long‐term clinical outcome. Of the 36 pts with recurrent AF, 20 pts have not had a repeat procedure. Conclusions: PVAI with non‐PVTA for longstanding persistent AF provides good long‐term AF control in over 70% of patients with infrequent (5%) AFL. AAD therapy and repeat PVAI may be required for this optimal outcome. (J Cardiovasc Electrophysiol, Vol. 23, pp. 806‐813, August 2012)     

Study Design of the Man and Machine Trial: A Prospective International Controlled Noninferiority Trial Comparing Manual with Robotic Catheter Ablation for Treatment of Atrial Fibrillation

Study Design of the Man and Machine Trial. Background: Pulmonary vein isolation (PVI) has become the cornerstone procedure for the treatment of symptomatic drug‐resistant atrial fibrillation (AF). At the present time, circumferential PVI (CPVI) using irrigated radiofrequency (RF) is the mostly used ablation technique. However, for CPVI, precise catheter navigation and excellent catheter stability is crucial thereby requiring experienced operators. Robotic navigation systems have been introduced to facilitate catheter navigation and to improve catheter stability, therefore potentially increasing procedural success and making CPVI accessible to less experienced operators. To date, no prospective randomized trial has evaluated the efficacy and safety of CPVI using RNS compared to manually performed ablation. Methods: In this prospective international multicenter noninferiority trial, 258 patients with either paroxysmal or short‐standing persistent AF will be randomized for comparison of PVI using either manual or robotic ablation. In all patients, CPVI will be performed using irrigated RF ablation in combination with a 3D mapping system. The primary endpoint of the trial is the absence of AF or atrial tachycardia without antiarrhythmic drug therapy during 12‐month follow‐up. Secondary endpoints will be evaluation of periprocedural complications and procedural data such as procedure time, fluoroscopy time, as well as the incidence of esophageal injury assessed by endoscopy within 48 hours after the procedure. Conclusion: The “Man and Machine Trial” is the first prospective international randomized controlled multicenter noninferiority trial to compare manually performed CPVI with robotically navigated CPVI, evaluating both the safety and efficacy of the 2 techniques during a 12‐month follow‐up period. (J Cardiovasc Electrophysiol, Vol. 24, pp. 40‐46, January 2013)     

Impact of Radiofrequency Characteristics on Acute Pulmonary Vein Reconnection and Clinical Outcome After PVAC Ablation

Impact of Radiofrequency Characteristics . Objective: The objective was to study the impact of radiofrequency (RF) characteristics on acute pulmonary vein reconnection (PVR) and outcome after PVAC ablation. PVI with additional ablation of PVR (PVI + PVR) was compared to PVI‐only. Methods: In 40 consecutive patients, after PVAC‐guided PVI, adenosine and a 1‐hour waiting time were used to unmask and ablate acute PVR (PVI + PVR group). RF‐characteristics and 1‐year AF freedom were compared post hoc to 40 clinically matched patients undergoing PVI only (PVI‐only group). Custom‐made software was used to assess RF characteristics of the PVAC applications needed to obtain baseline PVI. Results: There was no difference in clinical characteristics or baseline RF‐profile between both groups. Acute PVR was observed and ablated in 38 of 160 veins (24%). AF‐freedom after PVI + PVR was higher than PVI (85% vs 65%, P < 0.05). Within the PVI group, comparing patients with and without AF‐recurrence, the percentage of PVAC applications with high T° (>48°) but low power (<3W) was higher (28 ± 18% vs 11 ± 11%, P < 0.0001). Within the PVI + PVR group, when comparing PVs with and without PVR, the percentage of low power/high T° PVAC applications was also higher (27 ± 13% vs 13 ± 15%, P < 0.0001). Conclusions: (1) After PVAC ablation, 24% of PVs exhibit acute reconnection. Additional ablation of reconnection improves clinical outcome. (2) Acute reconnection as well as clinical recurrence of AF are characterized by PVAC ablation with a considerable number of applications with high temperature but low power. (3) If PV isolation is obtained with low power applications, a consistent use of both adenosine and waiting time is required. (J Cardiovasc Electrophysiol, Vol. 24, pp. 290‐296, March 2013)     

Acute pulmonary vein reconnection is a predictor of atrial fibrillation recurrence following pulmonary vein isolation

Purpose

Arrhythmia recurrence following pulmonary vein isolation (PVI) occurs predominantly due to the reconnection of previously isolated pulmonary veins (PVs). The prognostic implications of detection and treatment of acute PV reconnection are not well understood. We aim to examine the prognostic significance of acute PV reconnection on arrhythmia recurrence at 1 year following PVI.

Methods

This prospective study included 44 patients (22 men, 60?±?7 years) who underwent index PVI procedure for treatment of atrial fibrillation (AF). Acute PV reconnection and/or dormant PV conduction were assessed sequentially in response to a 30-min waiting period, intravenous isoproterenol infusion and/or adenosine. All cases of acute PV reconnection and/or dormant conduction were successfully targeted with additional ablation.

Results

Freedom from AF at 1 year was 75 % (83.3 % in paroxysmal and 65 % in persistent AF, p?=?ns). Acute PV reconnection and/or dormant conduction were evident in 16 of 44 patients (36.3 %). AF recurrence was documented in eight of 16 patients with, but only in three of 28 patients without acute reconnection (p?=?0.009). Three patients underwent a redo procedure, all from the group of patients with acute PV reconnection. In a multivariate model, acute PV reconnection was a strong independent predictor of arrhythmia recurrence (hazards ratio [HR], 6.36; 95 % confidence interval [CI], 1.12–31.6).

Conclusion

Identification of acute PV reconnection, even when successfully targeted, is a strong predictor of arrhythmia recurrence following PVI.     

Persistence of Pulmonary Vein Isolation After Robotic Remote‐Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome

Robotic Remote Ablation for AF . Aims: A robotic navigation system (RNS, Hansen?) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS‐guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome. Methods and Results: Sixty‐four patients (60.7 ± 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3‐dimensional left atrial reconstruction (NavX?). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12–34], procedure time: 180 [150–225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29–45] vs 12 [9–17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0–2) vs 2 (2–3); P = 0.006) and a longer LA‐PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year. Conclusion: Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1079‐1084)     

Outcomes of Ablation of Paroxysmal Atrial Fibrillation in Patients on Chronic Hemodialysis

AF Ablation in HD Patients . Introduction: It is not common for patients on chronic hemodialysis (HD) to undergo catheter ablation of atrial fibrillation (AF). We aimed to show the outcomes of AF ablation in the HD patients. Methods and Results: Thirty HD patients who underwent pulmonary vein (PV) isolation for drug refractory paroxysmal AF were retrospectively studied, and their AF recurrence free rate and frequency of periprocedural complications were compared to 60 age‐ and gender‐matched control patients not requiring HD. A nonirrigated ablation catheter was used in both patient groups. During a mean follow‐up period of 821 ± 218 days, 16 (54%) of the HD patients remained free from AF recurrence without any antiarrhythmic agents versus 47 (78%) of the control patients with an initial ablation (P = 0.013). A second ablation procedure was performed in 12 patients with an AF recurrence, and consequently 20 (67%) of the HD patients were in sinus rhythm compared to 53 (88%) of the controls during a follow‐up duration of 747 ± 221 after the last ablation (P = 0.012). Bleeding from the venipuncture site requiring a prolonged hospital stay was identified in 2 HD patients and 1 control subject, while no life‐threatening complications were observed in either patient group. Conclusion: Although the success rate of the PV isolation in HD patients was far from satisfactory, it may be considered as one of the therapeutic options for them. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1289‐1294, December 2012)     

Impact of adenosine-provoked acute dormant pulmonary vein conduction on recurrence of atrial fibrillation

Impact of ATP Reconduction on AF Recurrence. Introduction: Adenosine can be associated with acute recovery of conduction to the pulmonary veins (PVs) immediately after isolation. The objective of this study was to evaluate whether the response to adenosine predicts atrial fibrillation (AF) recurrence after a single ablation procedure in patients with paroxysmal AF. Methods and Results: A total of 109 consecutive patients (61 ± 10 years; 91 males) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. After PV antrum isolation (PVAI), dormant PV conduction was evaluated by an administration of adenosine in all patients. No acute reconnections were provoked by the adenosine in 70 (64.2%) patients (Group‐1), but they were provoked in at least one side of the ipsilateral PVs in 39 (35.8%) patients (Group‐2). All adenosine‐provoked dormant conductions were successfully eliminated by additional ablation applications. By 12 months after the initial procedure, 72 (66.1%) patients were free of AF recurrences without any antiarrhythmic drugs. A Cox regression multivariate analysis of the variables including the adenosine‐provoked reconductions, age, gender, duration of AF, presence of hypertension or structural heart disease, left atrial size, left ventricular ejection fraction, and body mass index demonstrated that adenosine‐provoked reconductions were an independent predictor of AF recurrence after a single ablation procedure (hazard ratio: 1.387; 95% confidence interval: 1.018–1.889, P = 0.038). At the repeat session for recurrent AF, conduction recovery was observed similarly in both groups (P = 0.27). Conclusion: Even after the elimination of any adenosine‐provoked dormant PV conduction, the appearance of acute adenosine‐provoked reconduction after the PVAI was an independent predictor of AF recurrence after a single AF ablation procedure. (J Cardiovasc Electrophysiol, Vol. 23 p. 256‐260, March 2012.)     

The Permanency of Pulmonary Vein Isolation Using a Balloon Cryoablation Catheter

Chronic PV Isolation With the Cryoballoon . Background: Because of its technical feasibility and presumed safety benefits, balloon cryoablation is being increasingly employed for pulmonary vein (PV) isolation. While acute isolation has been demonstrated in most patients, little data are available on the chronic durability of cryoballoon lesions. Methods and Results: Twelve atrial fibrillation patients underwent PV isolation using either a 23‐mm or 28‐mm cryoballoon. For each vein, after electrical isolation was verified with the use of a circular mapping cathether, 2 bonus balloon ablation lesions were placed. Gaps in balloon occlusion were overcome using either a spot cryocatheter or a “pull‐down” technique. A prespecified second procedure was performed at 8–12 weeks to assess for long‐term PV isolation. Acute PV isolation was achieved in all PVs in the patient cohort (n = 48 PVs), using the cryoballoon alone in 47/48 PVs (98%); a “pull‐down” technique was employed for 5 PVs (1 right superior pulmonary vein, 2 right inferior pulmonary veins, and 2 left inferior pulmonary veins). The gap in the remaining vein was ablated with a spot cryocatheter. During the second mapping procedure, 42 of 48 PVs (88%) remained isolated. One vein had reconnected in 2 patients, while 2 veins had reconnected in another 2 patients. All PVs initially isolated with the “pull‐down” technique remained isolated at the second procedure. Conclusions: Cryoballoon ablation allows for durable PV isolation with the use of a single balloon. With maintained chronic isolation in most PVs, it may represent a significant step toward consistent and lasting ablation procedures. (J Cardiovasc Electrophysiol, Vol. pp. 731‐737, July 2010)     

Long-term outcome of catheter ablation in patients with atrial fibrillation originating from the superior vena cava

Long‐Term Outcome of SVC AF Ablation. Introduction: Data of the long‐term clinical outcome after superior vena cava (SVC) isolation are limited. We aimed to evaluate the long‐term outcome in patients with atrial fibrillation (AF) who had triggers originating from the SVC and received catheter ablation of AF. Methods and Results: The study consisted of 68 patients (age 56 ± 12 years old, 32 males) who underwent the ablation procedure for drug‐refractory, symptomatic paroxysmal AF originating from the SVC since 1999. Group 1 consisted of 37 patients with AF initiated from the SVC only, and group 2 consisted of 31 patients with both SVC and pulmonary vein (PV) triggers. During a follow‐up period of 88 ± 50 months, the AF recurrence rate was 35.3% after a single procedure. The freedom‐from‐AF rates were 85.3% at 1 year and 73.3% at 5 years. In the baseline study, group 2 had larger left atrium (38 ± 4 mm vs 36 ± 5 mm, P = 0.04), left ventricle (50 ± 5 mm vs 46 ± 5 mm, P = 0.003), and PV diameters. Kaplan–Meier survival analysis showed a higher AF recurrence rate in group 2 compared to that in group 1 (P = 0.012). The independent predictor of an AF recurrence was a larger SVC diameter (P = 0.02, HR 1.4, 95% CI 1.1–1.8). Conclusion: Among the patients with paroxysmal AF originating from the SVC, 73% remained free of AF for 5 years after a single catheter ablation procedure. Superior vena cava isolation without PV isolation is an acceptable therapeutic strategy in those patients with AF originating from the SVC only. The SVC diameter was an independent predictor of AF recurrence. (J Cardiovasc Electrophysiol, Vol. 23, pp. 955‐961, September 2012)     

Pulmonary vein re-isolation for atrial fibrillation using duty-cycled phased radiofrequency ablation: safety and efficacy of a primary 2:1 bipolar/unipolar ablation mode

Purpose

Pulmonary vein isolation (PVI) using phased radiofrequency (RF) energy has been shown to be effective in the treatment of paroxysmal atrial fibrillation (AF). We characterize pulmonary vein (PV) conduction at repeat ablation in patients with AF after an initial successful PVI using phased RF technology and analyze the effects of a primary 2:1 ablation mode.

Methods and results

A primary 4:1 bipolar/unipolar mode in group A patients (n = 22) was compared with a primary 2:1 mode in group B (n = 22) acutely and during follow-up. Of all PVs, 81 % showed reconnection(s); 52 % of them had reconnected in all PVs. PVI was achieved in all patients without complications. Procedure and fluoroscopy times were shorter in group B (108 ± 15 vs. 126 ± 24 min and 17 ± 5 vs. 23 ± 7 min, respectively). This was attributed to a significant decrease of early PV reconnections within the first 30 min in 17 % of group B patients vs. 45 % of group A patients (p < 0.001). After 9.5 ± 4 months, recurrence of AF was detected in 5 of 22 patients (22.7 %) in group A vs. 3 of 22 patients (13.6 %) in group B (p = 0.722).

Conclusions

Phased RF energy applied by a 2:1 bipolar/unipolar mode seems safe and effective in redo-PVI procedures, resulting in a mid-term freedom from AF in 86.4%. Significant shorter procedure and fluoroscopy times compared with a primary 4:1 ablation mode during repeat PVI are mainly attributed to a lower incidence of acutely reconnected PVs within the first 30 min.     

Pulmonary vein isolation to treat paroxysmal atrial fibrillation: conventional versus multi-electrode radiofrequency ablation

Purpose

For patients with symptomatic atrial fibrillation (AF), a curvilinear multi-electrode ablation (MEA) catheter has been reported to be successful to achieve pulmonary vein (PV) isolation. However, this approach has not been compared prospectively with conventional PV isolation (CPVI) using a standard circular mapping catheter and 3D electro-anatomic mapping. In this prospective non-randomized study, we compared the efficacy of these two techniques.

Methods

Of 185 consecutive patients, age 54.6?±?10.1?years, with symptomatic paroxysmal AF (PAF), 96 patients underwent PV isolation by CPVI and 89 patients underwent MEA to isolate the PVs. CPVI was performed by encircling the left- and right-sided PVs. During MEA, the PV ablation catheter (Medtronic, USA) was used to isolate PVs with duty-cycled radiofrequency energy.

Results

The mean procedure time was 171.73?±?52.87?min for CPVI and 133.25?±?37.99?min for MEA, respectively (P?P?=?0.651). At 12?months, 80% of patients who underwent CPVI and 82% of patients who underwent MEA were free of symptomatic PAF off antiarrhythmic drug therapy (P?=?0.989). Among the variables of age, gender, duration and frequency of PAF, left ventricular ejection fraction, left atrial size, structural heart disease, and the ablation technique, only an increased left atrial size was an independent predictor of recurrent PAF. Left atrial flutter occurred after CPVI in two patients and after MEA ablation in three patients.

Conclusion

In patients undergoing catheter ablation for PAF, MEA and CPVI proved equally efficacious.