Mechanism, underlying substrate and predictors of atrial tachycardia following atrial fibrillation ablation using the second-generation cryoballoon

Abstract

Background: Data regarding atrial tachycardia (AT) following second-generation cryoballoon ablation (CBA) of atrial fibrillation (AF) are limited. Aim: To describe the incidence, mechanisms, and clinical predictors of ATs following CBA. Methods and results: In this retrospective single-center study 238 patients undergoing CBA for treatment of paroxysmal (91/238; 38.2%) or persistent AF were analyzed. During a mean follow-up of 11.9 AE 5.5 months recurrence of AF occurred in 49/238 patients (20.6%) and AT in 27/238 (11.3%). Twenty-six patients with AT and 14 with AF only underwent a redo ablation. The prevailing mechanism of AT was macroreentry [typical atrial flutter (AFL) (n = 10), left atrial macroreentry (n = 14), focal left-AT (n = 2)]. Non-cavotricuspid-isthmus-dependent macroreentry right-AT was mapped and ablated in 3 patients after initial AFL ablation. In a multivariate regression model, persistent type of AF (HR = 3.3; CI = 1.2-9.4), cardiomyopathy (HR = 3.5; CI = 1.5-8.4), treatment with beta-blockers (HR = 0.3; CI = 0.1-0.6), and pulmonary vein-abnormality (HR = 4.6; CI = 2.1-10.4) were independent predictors of AT. Substrate analysis revealed a significantly higher number of low voltage areas in the left atrium in patients with left-AT in comparison to patients with AF recurrence only (2.0; IQR=2.0À4.0 vs. 0.5; IQR = 0.0-2.25; p = 0.005). Conclusion:In this study, AT after CBA occurred in 11.3% of patients with macroreentry being the prevalent mechanism. All patients with left-AT presented with low voltage areas in the left atrium, suggesting a more progressive underlying fibrotic disease in these patients.

Ultra–high‐density mapping of conduction gaps and atrial tachycardias: Distinctive patterns following pulmonary vein isolation with cryoballoon or contact–force‐guided radiofrequency current

“…The occurrence of atrial tachycardias after stand‐alone PVI without substrate modification is a known but less frequent finding during reablation, with incidences between 2.8% and 11.3% 5,6,19‐21 . Several small studies comparing ATs after stand‐alone RFC or CB PVI have been conducted, and the results are very heterogeneous 5,6,19‐23 .…”

“…Different gap patterns have been described after index PVI with RFC versus CB 3,4 . A less‐common but clinically relevant finding is the occurrence of atrial tachycardia (AT) after stand‐alone PVI without prior substrate modification 5,6 …”

“…Data on UHDx mapping of PV reconnections and, in particular, AT following stand‐alone PVI are limited 4,5 . Therefore, repeat procedures with UHDx mapping and subsequent local impedance‐based ablation after an index PVI with contact–force (CF)‐guided RFC or with the second‐generation cryoballoon (CB) were compared in this study.…”

Approach to catheter ablation of left atrial flutters

“…Approximately, half of these ATs arise from the LA, with most of the remainder involving the cavotricuspid isthmus . A more recent study reported a higher incidence of organized AT after cryoballoon ablation for paroxysmal and persistent AF, and these tended to occur in patients who had low voltage areas in the LA suggesting an underlying fibrotic process …”

“…7,8 A more recent study reported a higher incidence of organized AT after cryoballoon ablation for paroxysmal and persistent AF, and these tended to occur in patients who had low voltage areas in the LA suggesting an underlying fibrotic process. 9 Macroreentry is the mechanism of most ATs after pulmonary vein isolation (about 60%-70%), whereas the remainder are classified as focal mechanisms. 10,11 When more extensive substrate ablation is performed for AF, ATs are more likely to occur.…”