Regional Differences in the Recovery Course of Tachycardia-Induced Changes of Atrial Electrophysiological Properties
Resource
CIRCULATION v.99 n.9 pp.1255-1264
Journal
CIRCULATION
Journal Volume
v.99
Journal Issue
n.9
Pages
1255-1264
Date Issued
1999
Date
1999
Author(s)
Lee, S.-H.
Lin, F.-Y.
Yu, W.-C.
Cheng, J.-J.
Kuan, P.
Hung, C.-R.
Chang, M.-S.
Chen, S.-A.
Abstract
Background-Regional differences in recovery of tachycardia- induced changes of atrial electrophysiological properties have not been well studied. Methods and Results-In the control group (5 dogs), atrial effective refractory period ( AERP) and inducibility of atrial fibrillation (AF) were assessed before and every 4 hours for 48 hours after complete atrioventricular junction (AVJ) ablation with 8- week VVI pacing. In experimental group 1 (15 dogs), AERP and inducibility of AF were assessed before and after complete AVJ ablation with 8-week rapid right atrial (RA) pacing (780 bpm) and VVI pacing. In experimental group 2 (7 dogs), AERP and inducibility of AF were assessed before and after 8- week rapid left atrial (LA) pacing and VVI pacing. AERP and inducibility and duration of AF were obtained from 7 epicardial sites. In the control group, atrial electrophysiological properties obtained immediately and during 48-hour measurements after pacing did not show any change. In the 2 experimental groups, recovery of atrial electrophysiological properties included a progressive recovery of AERP shortening, recovery of AERP maladaptation, and decrease of duration and episodes of reinduced AF. However, recovery of shortening and maladaptation of AERP and inducibility of AF was slower at the LA than at the RA and Bachmann's bundle. Conclusions-The LA had a slower recovery of tachycardia-induced changes of atrial electrophysiological properties, and this might play a critical role in initiation of AF.
Subjects
tachycardia
electrophysiology
atrium
FIBRILLATION
MECHANISM
MODEL
Type
journal article