Atrial fibrillation resulting from superior vena cava drivers addressed with cryoballoon ablation: Late reconnection at the site of phrenic nerve pacing catheter

Isolation of the superior vena cava by ultra-low temperature cryoablation

A patient with shocks from his ICD related to AF underwent redo ablation. The only identifiable target was the superior vena cava. This was isolated using ultra-low cryotherapy, eliminating episodes of AF.

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.

Comparison between superior vena cava ablation in addition to pulmonary vein isolation and standard pulmonary vein isolation in patients with paroxysmal atrial fibrillation with the cryoballoon technique

Background

Paroxysmal atrial fibrillation (PAF) can be triggered by non-pulmonary vein foci, like the superior vena cava (SVC). The latter is correlated with improved result in terms of freedom from atrial tachycardias (ATs), when electrical isolation of this vessel utilizing radiofrequency energy (RF) is achieved.

Objectives

Evaluate the clinical impact, in patients with PAF, of the SVC isolation (SVCi) in addition to ordinary pulmonary vein isolation (PVI) by means of the second-generation cryoballoon (CB)

Methods

A total of 100 consecutive patients that underwent CB ablation for PAF were retrospectively selected. Fifty consecutive patients received PVI followed by SVCi by CB application, and the following 50 consecutive patients received standard PVI. All patients were followed 12 months.

Results

The mean time to SVCi was 36.7 ± 29.0 s and temperature at SVC isolation was − 35 (− 18 to − 40) °C. Real-time recording (RTR) during SVCi was observed in 42 (84.0%) patients. At the end of 12 months of follow-up, freedom from ATs was achieved in 36 (72%) patients in the PVI only group and in 45 (90%) patients of the SVC and PV isolation group (Fisher’s exact test p = 0.039, binary logistic regression: p = 0.027, OR = 0.28, 95%CI = 0.09–0.86). In survival analysis, SVC and PV isolation group was also associated with improved freedom from ATs (log-rank test: p = 0.017, Cox regression: p = 0.026, HR = 0.31, 95%CI = 0.11–0.87).

Conclusion

Superior vena cava isolation with the CB in addition to PVI might improve freedom from ATs if compared to PVI alone at 1-year follow-up.