Nonreentrant focal activations in pulmonary veins in canine model of sustained atrial fibrillation.
Repetitive rapid activities are present in the pulmonary veins (PVs) in dogs with pacing-induced sustained atrial fibrillation (AF). The mechanisms are unclear. We induced sustained (>48 h) AF by rapidly pacing the left atrium (LA) in six dogs. High-density computerized mapping was done in the PVs and atria. Results show repetitive focal activations in all dogs and in 12 of 18 mapped PVs. Activation originated from the middle of the PV and then propagated to the LA and distal PV with conduction blocks. The right atrium (RA) was usually activated by a single large wavefront. Mean AF cycle length in the PVs (left superior, 82 +/- 6 ms; left inferior, 83 +/- 6 ms; right inferior, 83 +/- 4 ms) and LA posterior wall (87 +/- 5 ms) were significantly (P < 0.05) shorter than those in the LA anterior wall (92 +/- 4 ms) and RA (107 +/- 5 ms). PVs in normal dogs did not have focal activations during induced AF. No reentrant wavefronts were demonstrated in the PVs. We conclude that nonreentrant focal activations are present in the PVs in a canine model of pacing-induced sustained AF.
Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048-1865, USA.
Shengmei
S
Zhou
Che-Ming
CM
Chang
Tsu-Juey
TJ
Wu
Yasushi
Y
Miyauchi
Yuji
Y
Okuyama
Angela M
AM
Park
Akira
A
Hamabe
Chikaya
C
Omichi
Hideki
H
Hayashi
Lauren A
LA
Brodsky
William J
WJ
Mandel
Chih-Tai
CT
Ting
Michael C
MC
Fishbein
Hrayr S
HS
Karagueuzian
Peng-Sheng
PS
Chen
D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology*; D004195:Disease Models, Animal; D004285:Dogs; D004566:Electrodes; D006321:Heart / Q000503:physiopathology*; D006325:Heart Atria / Q000503:physiopathology; D010138:Pacemaker, Artificial; D011667:Pulmonary Veins / Q000502:physiology*