Segmental ostial ablation to isolate the pulmonary veins during atrial fibrillation: feasibility and mechanistic insights.
BACKGROUND
The purpose of this study was to determine the feasibility and mechanistic implications of segmental pulmonary vein (PV) ostial ablation during atrial fibrillation (AF).


RESULTS
Forty consecutive patients underwent PV isolation for AF. Among 125 PVs targeted for isolation, ablation was performed during AF in 70 veins and during sinus rhythm in 55 veins. A decapolar Lasso catheter was positioned near the ostium. During AF, ostial ablation was performed near the Lasso catheter electrodes that recorded a tachycardia with a cycle length shorter than in the adjacent left atrium. During sinus rhythm, ostial ablation was guided by PV potentials. Complete PV isolation was achieved in 70 PVs (100%) ablated during AF and in 53 PVs (96%) ablated during sinus rhythm (P=0.4). The mean durations of radiofrequency energy needed for isolation were 7.4+/-4.4 and 5.2+/-3.9 minutes during AF and sinus rhythm, respectively (P<0.01). Before ablation, an immediate recurrence of AF (IRAF), occurred after cardioversion in 18 of 40 patients, and IRAF was consistently abolished by PV isolation. The probability of AF termination during isolation of a PV was directly related to the extent of tachycardia in that vein. As more PVs were isolated, induction of persistent AF by rapid pacing became less likely.


CONCLUSIONS
Segmental ostial ablation guided by PV tachycardia during AF is feasible and as efficacious as during sinus rhythm. The responses to cardioversion, ablation, and rapid pacing observed in this study imply that IRAF is triggered by the PVs and that PV tachycardias may play an important role in the perpetuation of AF.
Division of Cardiology, Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0022, USA. oralh@umich.edu
Hakan
H
Oral
Bradley P
BP
Knight
Mehmet
M
Ozaydin
Aman
A
Chugh
Steve W K
SW
Lai
Christoph
C
Scharf
Sohail
S
Hassan
Radmira
R
Greenstein
Jihn D
JD
Han
Frank
F
Pelosi
S Adam
SA
Strickberger
Fred
F
Morady
D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000517:prevention & control / Q000601:surgery*; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation / Q000379:methods*; D004554:Electric Countershock; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D055502:Secondary Prevention; D013610:Tachycardia / Q000175:diagnosis; D016896:Treatment Outcome