Long chain n-3 polyunsaturated fatty acids reduce atrial vulnerability in a novel canine pacing model.
OBJECTIVE
Our objective was to assess the effect of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on atrial fibrillation (AF) vulnerability and atrial structure in a new model of atrial cardiomyopathy.


RESULTS
Dogs were studied in three groups: seven control dogs (UNPACED) and 24 dogs undergoing simultaneous atrioventricular pacing (for 2 weeks) assigned to placebo treatment (SAVP-PLACEBO, n = 12 dogs) or oral n-3 PUFAs (1 g/day) treatment (SAVP-PUFA, n = 12 dogs). SAVP-PUFA dogs had less AF inducibility (percentage of burst attempts leading to AF episodes: 5.5 +/- 7.4 vs. 20.4 +/- 14.2, P < 0.001) and maintenance [median AF duration: 601 s (377-1216) vs. 1598 s (1195-2400), P < 0.05] than SAVP-PLACEBO dogs. SAVP-PUFA dogs had significantly less local slowing of conduction and conduction heterogeneity than SAVP-PLACEBO dogs. SAVP-PUFA dogs had a significantly smaller increase in atrial matrix metalloproteinase-9 activity and in collagen type I and III messenger RNA expression (in arbitrary units) than SAVP-PLACEBO dogs (0.62 +/- 0.51 vs. 10.80 +/- 5.61, respectively for collagen I, P < 0.05; 1.66 +/- 0.48 vs. 5.24 +/- 1.16, respectively, for collagen III, P < 0.05).


CONCLUSIONS
n-3 PUFA supplementation can reduce AF vulnerability in a new canine pacing model of atrial cardiomyopathy. The mechanism may be related to attenuation of collagen turnover.
Laurent
Gabriel
G
Keenan Research Center, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, ON, Canada.
Moe
Gordon
G
Hu
Xudong
X
Holub
Bruce
B
Leong-Poi
Howard
H
Trogadis
Judy
J
Connelly
Kim
K
Courtman
David
D
Strauss
Bradley H
BH
Dorian
Paul
P
D000818:Animals; D001281:Atrial Fibrillation / Q000517:prevention & control*; D009320:Atrial Natriuretic Factor / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D004285:Dogs; D004452:Echocardiography; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000503:physiopathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D023421:Models, Animal; D009206:Myocardium / Q000473:pathology; D053773:Transforming Growth Factor beta1 / Q000235:genetics
D015525:Fatty Acids, Omega-3; D053773:Transforming Growth Factor beta1; D009320:Atrial Natriuretic Factor; D020780:Matrix Metalloproteinase 9