Dietary omega 3 fatty acids modulate the substrate for post-operative atrial fibrillation in a canine cardiac surgery model

作者：Mayyas Fadia; Sakurai Seiichiro; Ram Rashmi; Rennison Julie H; Hwang Eui Seock; Castel Laurie; Lovano Beth; Brennan Marie Luise; Bibus Douglas; Lands Bill; Barnard John; Chung Mina K; Van Wagoner David R^*

来源：Cardiovascular Research, 2011, 89(4): 852-861.

DOI：10.1093/cvr/cvq380

• Post-operative atrial fibrillation
• Omega-3 fatty acids
• Heart rate
• Endothelin-1
• Myeloperoxidase

Aims Pre-treatment with dietary omega 3 polyunsaturated fatty acids (omega 3-PUFA) has been reported to reduce the incidence of new-onset atrial fibrillation (AF) following cardiac surgery. In a canine cardiac surgery model, we evaluated the impact of dietary omega 3-PUFA on atrial electrophysiological properties, inflammatory markers, the atrial endothelin-1 (ET-1) system, and the expression and distribution of connexin 43.
Methods and results Adult mongrel dogs received either normal chow (NC, n = 11) or chow supplemented with fish oil (FO, 0.6 g omega 3PUFA/kg/day, n = 9) for 3 weeks before surgery. A left thoracotomy was performed, and the left atrial appendage (LAA) was excised. Atrial pacing/recording wires were placed, and the pericardium/chest was closed. The atrial ratio of omega 6/omega 3 lipids decreased from 15-20 in NC to 2-3 in FO. FO treatment lowered pre-surgical and stabilized post-surgical arachidonate levels. Peak neutrophil to lymphocyte ratio was lower and decayed faster in FO-treated animals. Extensive inflammatory cell infiltration was present in NC atria, but was reduced in FO-treated dogs. FO-treated animals had lower post-surgical atrial expression of inducible nitric oxide synthase (iNOS) and reduced plasma ET-1. Expression of ET-1 and inositol trisphosphate receptor type-2 proteins in the LAA was also reduced. FO treatment prolonged post-operative atrial effective refractory period, slowed heart rate, and enhanced heart rate variability. Importantly, AF (> 30 s) was inducible in four of six NC dogs, but no FO dogs.
Conclusion Dietary FO attenuated AF inducibility following cardiac surgery by modulating autonomic tone and heart rate. FO also reduced atrial inflammation, iNOS, and ET-1 expression.

• 出版日期2011-3