Pulsed-field ablation demonstrates superior pulmonary vein isolation durability at 90 days: Pooled analysis of protocol-mandated remapping data.

Wide-area antral pulmonary vein and posterior wall isolation by way of segmental nonocclusive applications using a novel radiofrequency ablation balloon

Catheter ablation for persistent atrial fibrillation in an elderly patient with cor triatriatum sinister

The procedural data of pulmonary vein (PV) isolation (PVI) for patients with atrial fibrillation using the second-generation laser balloon (LB2), which became available recently, remains unclear and were evaluated. Thirty consecutive patients (116 PVs) underwent PVI using LB2 (LB2 group) and were matched to 30 patients (116 PVs) treated with the first-generation laser balloon (LB1 group). The left atrial isolated surface area (ISA) (ratio of the total isolated antral surface area excluding PV to the total isolated antral surface area including the posterior wall) was also measured after LB2 PVI. PVI was achieved in 103/116 (89%) PVs and 108/116 (93%) PVs in the LB2 and LB1 groups, respectively, after the initial circular ablation (P=0.360) and in 115/116 (99%) PVs and 116/116 (100%) PVs in the LB2 and LB1 groups, respectively, at the end of the procedure (P=1.000). PV occlusion grade, categorized by the degree of PV occlusion, was significantly better in the LB2 group than in the LB1 group (P<0.001). Zero rotational maneuver was applicable in 23/116 (20%) PVs and 8/116 (7%) in the LB2 and LB1 groups, respectively (P=0.007). There was no significant difference in the procedural time, fluoroscopic time, or complications. The mean ISA after LB2 PVI was 53 ± 14%. The application number was the only independent predictor of successful PVI after initial circular LB2 ablation (adjusted odds ratio 0.860; 95% confidence interval 0.764-0.968; P=0.013). LB2 displays favorable PV occlusion characteristics and enables more zero rotational maneuvers.

The influence of varying energy settings on efficacy and safety of endoscopic pulmonary vein isolation

A new era of atrial fibrillation (AF) treatment began in 1997–1998 with the discovery that triggers within the pulmonary veins initiate AF and reports that elimination of these triggers is successful in treating AF in its paroxysmal form.1–3 However, in patients with persistent AF, the success rate of exclusive pulmonary vein isolation is substantially lower.4,5 To improve the outcome of persistent AF ablation, different ablation strategies have been explored, but to date the optimal strategy has not been defined. Although some groups argue that limited ablation, including pulmonary vein isolation and, if present, ablation of nonpulmonary vein triggers, is sufficient for persistent AF ablation, other groups, including ours, favor more extensive, substrate-based ablation in addition to pulmonary vein isolation. In this review, we will discuss the rationale for a substrate-based ablation strategy to treat persistent AF and show why elimination of triggers is not sufficient in most patients with persistent AF. Response by Roten et al on p 1232 In a simple model, an electric impulse in AF can form because of abnormalities in impulse generation (triggers) or can result from abnormal impulse propagation (reentry). By a strict definition, a trigger is a focal source of new impulse generation. The mechanism by which a new impulse can form is either abnormal automaticity or triggered activity. Trigger-ablation protocols target these sources of new impulse generation. Abnormal impulse propagation, on the other hand, depends on altered substrate properties causing nonuniform or slowed conduction. This in turn causes multiple forms of wave reentry thought to be responsible for AF perpetuation: random reentry (multiple wavelets), macro- and microreentry, or functional reentry (rotors). Substrate-based ablation strategies aim to abate abnormal impulse propagation and interrupt any form of atrial reentry. Triggers of paroxysmal AF are mainly located in the pulmonary …

POSTER PRESENTATIONS

Background: Circumferential pulmonary vein (PV) isolation has been widely accepted as catheter ablation for atrial fibrillation (AF). Dissociated PV activity (DPVA) may appear after PV isolation, however, the electrophysiological property and clinical implication of DPVA have not been revealed. Methods and Results: The study subjects were consecutive 37 patients (62±8 years, 28 men) with drug-refractory AF who underwent successful PV isolation. Electrophysiological property of left atrium (LA) and PV during and after PV isolation were investigated. Excluded 21 PVs without LA-PV connection before procedure, all of 112 PVs with successful isolation were analyzed. DPVA appeared in 14 PVs (13%) after PV isolation, from left superior PV in 7 (50%), right superior PV in 5 (36%) and left inferior PV in 2 (14%). Mean cycle length (CL) of DPVA was 5180±3080 ms. DPVA appeared in 9 of 37 PVs (24%) without existence of AF, but in 5 of 75 PVs (7%) with existence of AF during procedure (P=0.008). There was the tendency that the CL of DPVA was shorter with existence of AF compared to that without existence of AF (3792±1815 vs. 6682±3041 ms, P=0.08), and the suppression of DPVA was observed by over drive pacing inside of PV with PV capture in several cases. There was not significant relationship between the presence of DPVA and AF recurrence with 2-month blanking period after PV isolation. Conclusions: The presence of DPVA after PV isolation depended on the existence of AF during procedure, but was not significantly related to the AF recurrence after PV isolation. The long CL and suppressive maneuver with PV over drive pacing suggested the vulnerability of DPVA. Thus, these findings suggest that passive and/or spontaneous fibrillatory excitation in PV might suppress the automatic activity of myocardial sleeves in PV.

Mechanical esophageal deviation: an approach for pulmonary vein reconnection attributed to esophageal heating

Circumferential pulmonary vein (PV) isolation has been widely accepted for catheter ablation in patients with atrial fibrillation (AF). Dissociated PV activity might appear after PV isolation (PVI). However, little is known of dissociated PV activity. This study aimed to reveal the electrophysiological properties and clinical implications of dissociated PV activity. The study subjects were 52 patients (62 ± 7years, 38 men) who underwent PVI for AF. Electrophysiological properties of the left atrium (LA) and PVs during and after PVI were investigated. Out of 181 targeted PVs, 177 with successful isolation were analyzed. Dissociated PV activity appeared in 14 PVs (8%) in 12 patients (23%) after PVI; from the left superior PV in eight, right superior PV in five, and left inferior PV in one. The mean cycle length of dissociated PV activity was 4277 ± 2565ms. The presence of AF prior to achieving PVI was significantly higher in PV without dissociated PV activity (105 out of 163, 64%) than in PV with dissociated PV activity (five out of 14, 36%, P = 0.03). The observed dissociated PV activity was enhanced (new appearance or reduced cycle length) by isoproterenol and suppressed by pacing within the isolated PV. Dissociated PV activity, although influenced by uncertain factors such as overdrive suppression and autonomic situations, would be an indicator of LA-PV bidirectional block and might not be the target of additional ablation after PVI.

The utility of atrial pacing for identifying the electrical breakthrough sites between the left atrium and pulmonary veins

This editorial refers to ‘Efficacy of multi-electrode duty-cycled radiofrequency ablation for pulmonary vein disconnection in patients with paroxysmal and persistent atrial fibrillation’ by R.P. Beukema et al ., on page 502. Pulmonary vein (PV) isolation (PVI) is currently the most well-accepted ablation strategy for the treatment of atrial fibrillation (AF) because of the demonstration of a pathophysiological role of PV myocardium and a simple and unambiguous endpoint. The technique as originally described utilizes one circumferential mapping catheter placed within the PVs and another ablation catheter in the left atrium (LA) sequentially targeting earliest activation from the LA into the PVs.1 A third catheter placed in the distal coronary sinus is mainly useful to distinguish far-field LA activation from local PV myocardial activation in the left PVs. Appropriate ablation progressively isolates the PV by disconnecting each LA input one by one. Two variants of PVI are practised: circumferential PV ablation (CPVA) which relies on the anatomical creation of a complete isolation barrier and the segmental technique or its variants which depend upon electrical activation to pinpoint the precise input(s) and perform targeted ablation. Although the CPVA technique started life as a single (ablation) catheter-based technique, both techniques as currently practiced require appropriate and stable positioning of two catheters, one to ablate and the other to map and verify isolation. The circular mapping catheter once introduced within a PV of choice should be stable enough to allow the operator to use both hands to manipulate the ablation catheter tip to desired locations around the PV ostial circumference. For anatomical reasons however, this is frequently difficult with the right inferior PV (RIPV) and successful isolation often seems to require more than two hands (or an obedient and stoic assistant!). Both PVI procedures are time consuming including the time taken for each individual ablation, … *Corresponding author. Tel: +41 22 3727202; fax: +41 22 3727229, Email: dipen.shah{at}hcuge.ch

BackgroundThe recurrence of arrhythmias after pulmonary vein (PV) isolation in patients undergoing atrial fibrillation ablation is often due to PV reconnection, but it can also be attributed to an incomplete...

Pulmonary vein (PV) isolation (PVI) has been recently proposed as an effective technique to cure atrial fibrillation (AF). The aim of this study was to investigate the efficacy of a novel technique utilizing a computerized three-dimensional mapping system (QMS2) with a multielectrode basket catheter (MBC) for PVI and to reveal the relation between the style of breakthrough and the network of the PV musculature. Sixty-five consecutive patients with frequent AF attacks underwent PV mapping with a 31-mm MBC, and a three-dimensional color animation of the potential map was constructed by the QMS2. The animation color schema was arranged to minimize the low-amplitude left atrial (LA) potentials and emphasize the high-amplitude PV potentials (PVPs). The longitudinal PVP map enabled us to recognize the true breakthroughs and reveal the network of the PV musculature. A total of 205 PVs (65 left superior PVs, 65 right superior PVs, 57 left inferior PVs and 18 right inferior PVs) were mapped and successful PVI was achieved in all PVs, except one that had no PVPs, with a mean radiofrequency duration of 7 +/- 5 minutes per PV. In about 90% of the PVs, a final radiofrequency application eliminated all the distal PVPs simultaneously because the PVI was performed at the appropriate LA-PV junction. A single segmental breakthrough was detected in 17 PVs, single broad breakthrough in 83 PVs, multiple separate breakthroughs with a distal connection between the PV musculatures extending from each separate breakthrough in 88 PVs and multiple separate breakthroughs without that connection in 16 PVs. During the follow-up period, fifty-one (78%) patients were free of symptomatic AF without any antiarrhythmic drugs after multiple procedures (thirty-three (51%) of those patients after the first procedure) and no PV stenosis was found. Computerized three-dimensional potential mapping can be useful for PVI because it can not only identify the true breakthrough, but can also confirm the elimination of the breakthroughs by the change in the activation sequence through the network of the PV musculature.

Aim. To study changes in pulmonary vein ostia strain after radiofrequency (RFA) and cryoballoon ablation (CBA) in patients with paroxysmal atrial fibrillation (AF) by intracardiac echocardiography.Methods. Patients with paroxysmal AF (n=41) aged 60.1±7.1 years and duration of the disease 7.7±4.8 years were included in the study. Pulmonary vein (PV) isolation was performed with RFA (n=23) and CBA (n=18). All patients underwent transthoracic and intraoperative intracardiac echocardiography. Longitudinal strain of PV ostia was assessed before and after isolation.Results. Groups were comparable in main clinical parameters. Regress of PV ostia strain after RFA and CBA was achieved in all of PV, which corresponded to complete PV isolation. Remarked trend toward a more pronounced regression of PV ostia longitudinal strain after CBA compared with RFA for left superior (10±0.7% and 6.1±0.8% respectively, p&lt;0.001) and right inferior PV (9.3±0.7% vs 7.3±0.6%, p&lt;0.001) requires continued observation and analysis of data in a larger group. There were no complications.Conclusion. PV isolation is accompanied by a significant change in their longitudinal strain using intracardiac echocardiography both after CBA and after RFA.

A 70-year-old man with atrial fibrillation underwent pulmonary vein (PV) isolation (PVI). Bigeminal concealed PV depolarizations persisted within the right superior PV throughout the PVI. Though the PV depolarizations was suppressed after successful PVI, PV depolarization, following a slow intrinsic PV automatic rhythm, was observed. The coupling interval of the PV depolarizations during the PV automaticity was identical to that of the PV depolarizations during sinus rhythm before the PVI. This case demonstrated that PV depolarization does not always depend on an intact left atrial input, but may depend on some types of triggering electrical activity.