Autonomic mechanism to explain complex fractionated atrial electrograms (CFAE).
OBJECTIVE
To simulate complex fractionated atrial electrograms (CFAE) during sustained atrial fibrillation (AF) in experimental animals.


BACKGROUND
The mechanism(s) underlying CFAE has not been fully elucidated.


METHODS
Twenty-two dogs were subjected to a right and/or left thoracotomy. A gauze patch soaked with acetylcholine (ACh) was placed on the right atrial appendage (RAA) to induce sustained AF. During AF, varying concentrations of ACh (1, 10, 100 mM) were "painted" on the RA where electrograms showed regular organized activity. In another six dogs, anterior right ganglionated plexi (ARGP) near the sino-atrial node and inferior right GP (IRGP) at the junction of inferior vena cava and atria were sequentially ablated. In five dogs, ACh was injected into ARGP to induce CFAE.


RESULTS
During sustained AF, local "painting" with ACh 1 mM and 10 mM induced intermittent CFAE in 1 of 11 and 10 of 11 dogs, respectively. With 100 mM ACh, all 11 showed CFAE (two intermittent, nine continuous). In six other dogs, continuous CFAE induced by topical application of 100 mM ACh were markedly attenuated by ARGP + IRGP ablation. In another five of five dogs, ACh injection into ARGP induced a gradient of CFAE with the continuous CFAE always occurring near the ARGP and CFAE also occurring at left pulmonary vein-atrial junctions. During ARGP ablation, AF was terminated in all five dogs immediately after regularization of the rotor-like electrograms or continuous CFAE.


CONCLUSIONS
This study demonstrates an autonomic basis for CFAE formation, suggesting that graded hyperactive states of the autonomic nervous system (ANS) may induce various types of CFAE observed clinically.
Lin
Jiaxiong
J
Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China.
Scherlag
Benjamin J
BJ
Zhou
Jing
J
Lu
Zhibing
Z
Patterson
Eugene
E
Jackman
Warren M
WM
Lazzara
Ralph
R
Po
Sunny S
SS
D000109:Acetylcholine; D000818:Animals; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017115:Catheter Ablation; D004195:Disease Models, Animal; D004285:Dogs; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*
D000109:Acetylcholine