Pulsed field ablation for atrial tachycardia following prior persistent atrial fibrillation ablation and resistant to radiofrequency energy

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background There is a limited knowledge of immediate and long-term efficacy of pulsed field ablation for residual atrial tachycardia (AT) following (longstanding) persistent atrial fibrillation (AF) ablation and resistant to prior radiofrequency ablation (RFA). Purpose To present immediate effects of PFA (Farapulse) in a series of patients with repeat ablation for residual atrial tachycardia (AT) resistant to prior RFA. Methods and results In 5-11/2022, of 23 patients scheduled for PFA, 19 patients (64±7 years, 3 females) underwent PFA for left atrial (LA) AT resistant to RFA in first (n=4), second (n=11), third (n=3), and fourth (n=1) repeat ablation, respectively, after primary persistent AF ablation (4 patients were redirected to RFA for septal/right atrial AT source found by 3D mapping). At the procedure onset, persistent AT was ongoing (n=15) or was induced (n=4; AF induced and subsequently converted into AT in 3 patients). Mapping/ablation strategy was directed according to CS activation/entrainment to: 1) no 3D mapping and direct PFA (n=11); 2) PFA directly after 3D LA mapping (n=5); 3) PFA following RFA after 3D LA mapping (n=3). Total of 29 ATs was found (1,2, and 3 ATs in 12, 4, and 3 patients, respectively). Localized AT sources (n=16) dominated over macroreentry (MR) ATs (8 perimitral, 4 roof-dependent, 1 typical flutter). Only MR ATs, only localized ATs, and both MR+localized ATs were present in 7, 4, and 8 patients, respectively. All ATs were stopped with 5±9 PFA applications at the site of AT source and remained non-inducible. In 3 patients with initial ineffective RFA (6, 11, 6 minutes) within the same procedure, subsequent PFA terminated the AT with 1, 4, and 1 application respectively. Procedure and fluoroscopy times were 104±29 and 12±4 minutes, no complication occurred. Conclusion PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure.