Electrophysiological Mapping and Histological Examinations of the Swine Atrium with Sustained (>= 24 H) Atrial Fibrillation: A Suitable Animal Model for Studying Human Atrial Fibrillation
Resource
CARDIOLOGY v.99 n.2 pp.78-84
Journal
CARDIOLOGY
Journal Volume
99
Journal Issue
2
Pages
78
Date Issued
2003
Date
2003
Author(s)
Lin, Chih-Shen
Du, Chao-Cheng
Wu, Tsu-Juey
Chen, Shih-Ping
Lee, Wen-Chuan
Yang, Ping-Cheng
Tseng, Yung-Zu
Lien, Wen-Pin
Huang, Shoei K. Stephen
Abstract
Objectives: Interventional elimination of chronic persistent atrial fibrillation (AFib) remains difficult. An animal model mimicking the clinical situation is important. Methods and Results: Twenty-five adult pigs were implanted with a high-speed atrial pacemaker. After continuous pacing at 600 bpm for 6 weeks, 20 (91 %) of the 22 survivals developed sustained AFib lasting for at least 24 h. Epicardial dense mapping revealed multiple coexisting reentrant wavelets in the left and the right atrium (LA and RA, respectively; 10.6 +/- 2.9 vs. 7.6 +/- 2.4 wavelets/cm( 2)/s; p < 0.002). The mean local A-A intervals were 87.2 +/- 14.6 ms in the LA and 103.3 +/- 19.0 ms in the RA (p < 0.0002). Acute termination of sustained AFib was successful in 3 of the 5 pigs by propafenone, but in none of the 6 by dl-sotalol. Epicardial cryothermal ablation failed to terminate any AFib by compartmentalization of the RA free wall alone (4 pigs) or together with the LA appendage (4 pigs). Electron microscopic examination demonstrated diffuse perinuclear myolysis, myofibrillar fragmentation and mitochondrial crystal disruption in the atrium. Conclusions: Pacing- induced sustained AFib (greater than or equal to24 h) in adult pigs is a feasible and efficient animal model with electrophysiological and histological characteristics closely similar to those seen in humans. Received: July 20, 2002 Accepted after revision: January 28, 2003 Copyright (C) 2003 S. Karger AG, Basel.
Subjects
RADIOFREQUENCY ABLATION
CATHETER
HEART
AMIODARONE
SURGERY
Type
journal article