Complete title: Low Voltage Zones as the Atrial Fibrillation Substrates:
Relationship with Atrial Fibrillation Initiation, Perpetuation, and
Termination.
Abstract
Background: Low voltage Zones (LVZ) were usually targeted for ablation
in atrial fibrillation (AF). But its relationship with AF initiation,
maintenance, and termination remains to be studied. We tried to explore
the relationships. Methods and Results: Consecutive AF patients were
enrolled for assessment AF inducibility, AF duration or AF termination
before ablation. Inducible AF was defined if induced AF last over 30
seconds. Sustainable AF was defined if it last over 300 seconds.
Terminable AF was defined if it could be cardioverted into sinus rhythm
within 1-hour after ibutilide administration. Voltage mapping was
performed in sinus rhythm for all patients before stimulation or after
cardioversion. LVZ was quantified as the percentage of LVZ
area(LVZ%)to left atrium (LA) body surface. A total of 86 patients
enrolled for AF induction and 36 for AF termination. 32 (37.2%)
patients had inducible AF, 24 (27.9%) were sustainable, and 12 (33.3%)
were terminable. Inducible AF patients had higher LVZ% in anterior wall
(18.6±24.6 vs. 7.0±12.1, P=0.014). Global LVZ% was not different
between inducible and uninducible AF patients. Global LVZ% was higher
in patients with sustainable AF or interminable AF (LVZ%: sustainable
vs unsustainable AF: 10.6±12.1 vs. 0.8±0.8, p=0.001; terminable vs.
interminable: 17.1±13.5vs.40.6±24.5, p<0.001). Sustainable AF
had larger LVZ% in roof, anterior wall, septum, floor. Interminable AF
patients had higher LVZ% in anterior wall, septum, posterior wall and
floor. Higher LVZ% was independent risk factor of recurrence (OR=1.015,
P=0.042). Conclusion: The association between LVZ with AF initiation,
perpetuation and termination were different.