Safety and feasibility of electrical isolation of the superior vena cava in addition to pulmonary vein ablation for paroxysmal atrial fibrillation using the cryoballoon: lessons from a prospective study

Superior vena cava isolation using a pentaspline pulsed-field ablation catheter: feasibility and safety in patients undergoing atrial fibrillation catheter ablation

AIMS

Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation.

METHODS AND RESULTS

One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred.

CONCLUSION

SVC isolation using a pentaspline PFA catheter is feasible and safe.

Cryoballoon ablation of non-PV triggers in persistent atrial fibrillation

Cryoballoon-based catheter ablation has emerged as an efficacious and safe therapeutic intervention for patients with paroxysmal atrial fibrillation (PAF). PAF is primarily associated with the triggers in the pulmonary vein (PV). However, persistent atrial fibrillation (PeAF) is a complex condition that involves changes in the atrial substrate and the presence of non-PV triggers. Therefore, a comprehensive treatment approach is necessary for patients with PeAF. Utilizing a 3D electroanatomical map, the radiofrequency-based ablation technique adeptly identifies and targets the atrial substrate and non-PV triggers. On the other hand, the cryoballoon-based AF ablation was initially designed for PV isolation. However, its single-shot feature makes it a great choice for electrophysiologists looking to address non-PV triggers. It is possible to target the left atrial appendage (LAA), superior vena cava (SVC), left atrial roof, and posterior wall using the apparatus's unique configuration and ablation abilities. This review focuses on the increasing literature regarding cryoballoon-based methods for non-PV trigger ablation. Specifically, it delves into the technical procedures used to isolate the LAA, SVC, and ablate the left atrial roof and posterior wall.

Pulsed field ablation of superior vena cava in paroxysmal atrial fibrillation: a case report

Paroxysmal atrial fibrillation originates most commonly in the pulmonary veins. However, the superior vena cava has proved to be arrhythmogenic in some cases. Pulsed field ablation, an emerging ablation technology, selectively affects myocardial tissue. Herein, we present a case of paroxysmal atrial fibrillation in a 64-year-old man who was admitted to our hospital for pulsed field ablation. The tachycardia was recurrent despite four successful pulmonary vein isolations. The superior vena cava was determined to be involved in arrhythmogenesis. The atrial fibrillation terminated immediately after the pulsed field ablation discharge at the superior vena cava.

Empirical superior vena cava isolation improves outcomes of radiofrequency re-ablation in pulmonary vein isolation non-responders: A 2-center retrospective study in China

Background

Pulmonary vein isolation (PVI) is the standard ablation strategy for treating atrial fibrillation (AF). However, the optimal strategy of a repeat procedure for PVI non-responders remains unclear.

Objective

This study aims to investigate the incidence of PVI non-responders in patients undergoing a repeat procedure, as well as the predictors for the recurrence of repeat ablation.

Methods

A total of 276 consecutive patients who underwent repeat ablation from August 2016 to July 2019 in two centers were screened. A total of 64 (22%) patients with durable PVI were enrolled. Techniques such as low voltage zone modification, linear ablation, non-PV trigger ablation, and empirical superior vena cava (SVC) isolation were conducted.

Results

After the 20.0 ± 9.9 month follow-up, 42 (65.6%) patients were free from atrial arrhythmias. A significant difference was reported between the recurrent and non-recurrent groups in non-paroxysmal AF (50 vs. 23.8%, p = 0.038), diabetes mellitus (27.3 vs. 4.8%, p = 0.02), and empirical superior vena cava (SVC) isolation (28.6 vs. 60.5%, p = 0.019). Multivariate regression analysis demonstrated that empirical SVC isolation was an independent predictor of freedom from recurrence (95% CI: 1.64-32.8, p = 0.009). Kaplan-Meier curve demonstrates significant difference in recurrence between empirical and non-empirical SVC isolation groups (HR: 0.338; 95% CI: 0.131-0.873; p = 0.025).

Conclusion

About 22% of patients in repeat procedures were PVI non-responders. Non-paroxysmal AF and diabetes mellitus were associated with recurrence post-re-ablation. Empirical SVC isolation could potentially improve the outcome of repeat procedures in PVI non-responders.

Initial experience of a novel method for electrical isolation of the superior vena cava using cryoballoon in patients with atrial fibrillation

BACKGROUND

Damage to the sinus node (SN) has been described as a potential complication of superior vena cava (SVC) isolation. There have been reports of permanent SN injury requiring pacemaker implantation during isolation of the SVC.

HYPOTHESIS

It is safe and effective to isolate SVC with the second-generation 28-mm cryoballoon by using a novel method.

METHODS

Forty-three patients (including six redo cases) with SVC-related atrial fibrillation (AF) from a consecutive series of 650 patients who underwent cryoballoon ablation were included. After pulmonary vein isolation was achieved, if the SVC trigger was identified, the SVC was electrically isolated using the cryoballoon. First, the cryoballoon was inflated in the right atrium (RA) and advanced towards the SVC-RA junction. After total occlusion was confirmed by dye injection with total retention of contrast in the SVC, the SVC-RA junction was determined. Next, the cryoballoon was deflated, advanced into SVC, then reinflated, and pulled back gently. The equatorial band of the cryoballoon was then set slightly (4.32 ± 0.71 mm) above the SVC-RA junction for isolation of the SVC.

RESULTS

Real-time SVC potential was observed in all patients during ablation. The mean time to isolation was 24.5 ± 10.7 s. The SVC was successfully isolated in all patients. The mean number of freeze cycles was 2.5 ± 1.4 per patient, and the mean ablation time was 99.8 ± 22.7 s. A transient phrenic nerve (PN) injury occurred in one patient (2.33%). There were no SN injuries. Freedom from AF rates at 6 and 12 months was 97.7% and 93.0%, respectively.

CONCLUSIONS

This novel method for SVC isolation using the cryoballoon is safe and feasible when the SVC driver during AF is determined and could avoid SN injury. PN function should still be carefully monitored during an SVC isolation procedure.

Cryoballoon ablation beyond pulmonary vein isolation in the setting of persistent atrial fibrillation

INTRODUCTION

Catheter ablation has been demonstrated to be a safe and an effective treatment for drug resistant atrial fibrillation (AF); electrical isolation of pulmonary veins (PVI) is the main strategy in paroxysmal AF, since pulmonary vein triggers have a pivotal role in its pathogenesis; non-paroxysmal AF is a complex arrhythmia that results from the interplay of a substrate, namely AF-induced electrical and structural atrial remodeling, and a trigger that can be often found outside pulmonary veins, namely non-pulmonary veins triggers.

AREAS COVERED

The aim of this review is to provide a state-of-the-art overview of non-pulmonary veins triggers with special focus on cryoballoon (CB) catheter ablation.

EXPERT OPINION

Besides PVI, CB catheter ablation of non-pulmonary veins triggers is a novel and promising strategy for non-paroxysmal AF.

Procedure characteristics and outcomes of atrial fibrillation ablation procedures using cryoballoon versus radiofrequency ablation: A report from the GWTG-AFIB registry

INTRODUCTION

Cryoballoon ablation (CBA) is an alternative to radiofrequency ablation (RFA) for ablation of atrial fibrillation (AF) and real-world comparisons of this strategy are lacking. As such, we sought to compare patient and periprocedural characteristics and outcomes of CBA versus RFA in the Get With the Guidelines AFIB Registry.

METHODS

Categorical variables were compared via the χ² test and continuous variables were compared via the Wilcoxon rank-sum test. Adjusted analyses were performed using overlap weighting of propensity scores.

RESULTS

A total of 5247 (1465 CBA, 3782 RFA) ablation procedures were reported from 33 sites. Those undergoing CBA more often had paroxysmal AF (60.0% vs. 48.8%) and no prior AF ablation (87.5% vs. 73.8%). CHA₂ DS₂ -VASc scores were similar. Among de novo ablations, most ablations involved intracardiac echocardiography and electroanatomic mapping, but both were less common with CBA (87.3% vs. 93.9%, p < .0001, and 87.7% vs. 94.6%, p < .0001, respectively). CBA was associated with shorter procedures (129 vs. 179 min, p < .0001), increased fluoroscopy use (19 vs. 11 min, p < .0001), and similar ablation times (27 vs. 35 min, p = .15). Nonpulmonary vein ablation was common with CBA: roof line 38.6%, floor line 20.4%, cavotricuspid isthmus 27.7%. RFA was associated with more total complications compared to CBA (5.4% vs. 2.3%, p < .0001), due to more volume overload and "other" events, although phrenic nerve injury was more common with CBA (0.9% vs 0.1%, p = .0001). In the adjusted model, any complication was less common among CBA cases (odds ratio, 0.45; confidence interval, 0.25-0.79, p = .0056).

CONCLUSION

CBA was associated with fewer complications, and shorter procedure times, and greater fluoroscopy times, compared to RFA. Nonpulmonary vein ablation and electroanatomic mapping system use was common with CBA.