Guidewire Entrapment in Pulmonary Veins During Pulsed Field Ablation of Atrial Fibrillation: A Case Series

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

Successful transseptal puncture and cryoballoon ablation of symptomatic paroxysmal atrial fibrillation via jugular access in a patient with bilateral thrombotic femoral vein occlusion

AimsWhen it occurs, pulmonary vein (PV) stenosis after atrial fibrillation (AF) ablation is associated with significant morbidity. Even mild-to-moderate PV narrowing may have long-term implications. Unlike thermal ablation energies, such as radiofrequency (RF) or cryothermy, pulsed field ablation (PFA) is a non-thermal modality associated with less fibrotic proliferation. Herein, we compared the effects of PFA vs. thermal ablation on PV narrowing after AF ablation.Methods and resultsADVENT was a multi-centre, randomized, single-blind study comparing PFA (pentaspline catheter) with thermal ablation—force-sensing RF or cryoballoon (CB)—to treat drug-refractory paroxysmal AF. Pulmonary vein diameter and aggregate cross-sectional area were obtained by baseline and 3-month imaging. The pre-specified, formally tested, secondary safety endpoint compared a measure of PV narrowing between PFA vs. thermal groups, with superiority defined by posterior probability > 0.975. Among subjects randomized to PFA (n = 305) or thermal ablation (n = 302), 259 PFA and 255 thermal ablation (137 RF and 118 CB) subjects had complete baseline and 3-month PV imaging. No subject had significant (≥70%) PV stenosis. Change in aggregate PV cross-sectional area was less with PFA (−0.9%) than thermal ablation (−12%, posterior probability > 0.999)—primarily driven by the RF sub-cohort (−19.5%) vs. CB sub-cohort (−3.3%). Almost half of all PFA PV diameters did not decrease, but the majority (80%) of RF PVs decreased, regardless of PV anatomic location.ConclusionIn this first randomized comparison of PFA vs. thermal ablation, PFA resulted in less PV narrowing—thereby underscoring the qualitatively differential and favourable impact of PFA on PV tissue.

Research Needs and Priorities for Catheter Ablation of Atrial Fibrillation

Pulmonary vein reconnections at time of repeat procedure, variations by ablation modality

Atrial flutter following ethanol infusion in the vein of Marshall

Thermal ablation for atrial fibrillation (AF) exerts a variable additive cardiac neuromodulation effect, primarily via the right anterior ganglionated plexus (RAGP), located between the right superior pulmonary vein (RSPV) and superior vena cava (SVC). The impact of non-thermal pulsed field ablation (PFA) on neuromodulation remains unclear. Our objective was to compare the spatiotemporal neuromodulation effect between thermal and non-thermal AF ablation. Consecutive paroxysmal AF patients undergoing either first-time cryoballoon ablation (CBA) or PFA with pre-procedural cardiac computed tomography (CT) were evaluated. Anatomic CT evaluation included measurement of the shortest distance between RSPV and SVC (RSPV-SVC distance). Changes in heart rate (HR) were assessed via electrocardiograms during and after ablation. A total of 280 patients (CBA,n = 210; PFA,n = 70) were included, with similar baseline characteristics between both groups. Significant intraprocedural HR increase (ΔHR ≥ 15bpm) was observed in 116 patients: CBA (n = 88, 42%), PFA (n = 28, 40%), p = 0.779. Although there was no difference in baseline HR between CBA vs PFA groups, HR at the end of the procedure was higher only in CBA group (75 ± 11bpm vs 66 ± 11bpm; p < 0.001). Multivariable analysis identified the RSPV-SVC distance (OR 0.607; 95% CI 0.445-0.775; p < 0.001) and younger age (OR 0.950; 95% CI 0.905-0.993; p = 0.030) as independent predictors of an intraprocedural ΔHR ≥ 15bpm. Both CBA and PFA for AF modulate the RAGP, particularly in patients with a shorter RSPV-SVC distance. However, neuromodulation with PFA is only transient during the procedure.

Understanding the structural remodeling and reverse remodeling of the left atrium (LA) and pulmonary vein (PV) after radiofrequency ablation of atrial fibrillation (AF) may provide important insights into the mechanism and management of AF. This study used magnetic resonance angiographic (MRA) images to investigate changes in PV and LA morphologies before and more than 1 year after ablation. Forty-five patients (36 men and 9 women, mean age 60 +/- 13 years) who underwent MRA before and more than 12 months (mean 21 +/- 11) after ablation of paroxysmal AF were included in the study. The patients were divided into two groups: group I included 35 patients without AF recurrence, and group II included 10 patients with late (>1 month postablation) recurrence of AF. The sizes of the LA and nonablated PV were compared before and after ablation. In group I, significant reduction of ostial area of both superior PVs was noted (left superior PV: from 2.85 +/- 0.67 to 2.59 +/- 0.73 cm2; right superior PV: from 2.89 +/- 0.85 to 2.60 +/- 0.73 cm2, both P <0.001). Geometric alteration toward a round shape was noted in the ostia of superior PVs during follow-up (eccentricity of right superior PV and left superior PV decreased from 0.31 +/- 0.10 to 0.22 +/- 0.13 and from 0.27 +/- 0.11 to 0.19 +/- 0.13, respectively, both P <0.01). However, LA volume showed only borderline reduction (from 61.52 +/- 19.06 to 56.64 +/- 17.13 mL, P=0.05). In group II, significant dilation of the LA (from 61.14 +/- 17.54 to 78.73 +/- 25.27 mL, P=0.004) and right superior PV (from 3.41 +/- 1.12 to 4.08 +/- 1.31 cm2, P=0.016) was noted during follow-up. Ostial area and eccentricity of the left superior, left inferior, and right inferior PVs and LA were similar before and after ablation. Structural remodeling of the superior PVs and LA can be reversible after successful ablation without AF recurrence; however, late recurrence of AF is associated with progressive LA dilation.

Epicardial potential sources of atrial arrhythmias, such as the ligament of Marshall, are in close proximity with, and electrically connected to, the left superior pulmonary vein. Ectopic activity arising from these areas may be difficult to differentiate from ectopy that, according to endocardial only mapping, originates in the left superior pulmonary vein. We hypothesized that in patients with paroxysmal atrial fibrillation (AF) apparently originating in the left pulmonary veins, mapping through the distal coronary sinus might identify possible epicardial locations of the arrhythmogenic focus. Forty patients (age 48 +/- 12 years) who underwent catheter ablation for paroxysmal AF were studied by epicardial mapping through the distal, superoposterior coronary sinus. Catheterization of the distal coronary sinus in order to approach the ostium of the left superior pulmonary vein was feasible in 14 of 19 patients with AF originating in the left superior vein (11 patients) or inferior pulmonary vein (3 patients) according to endocardial mapping criteria. In 2 patients, the sole focus of atrial tachycardia/fibrillation was epicardial with earliest activation clearly preceding electrograms recorded at the os of the left superior pulmonary vein or any other endocardial mapping site. Epicardial potentials separated from atrial electrograms were present during sinus rhythm in both patients and during atrial tachycardia in one patient. Catheter ablation through the coronary sinus rendered the arrhythmia noninducible in both patients without abolishing epicardial potentials in one of them. In patients with paroxysmal AF apparently originating from the left superior or inferior pulmonary vein, detailed epicardial mapping through the distal coronary sinus might identify epicardial locations of the arrhythmogenic focus.

Pulmonary vein reconduction is common in patients undergoing re-ablation after first-time pulsed field ablation for atrial fibrillation

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

Preferential properties with decremental conduction of the Marshall vein between the coronary sinus and left superior pulmonary vein

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

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