title: Effect of dietary omega-3 fatty acids on the heart rate and the heart rate variability responses to myocardial ischemia or submaximal exercise.
abstract: The consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs) has been reported to decrease resting heart rate (HR) and increase heart rate variability (HRV). However, the effects of n-3 PUFAs on these variables in response to a physiological stress (e.g., exercise or acute myocardial ischemia), particularly in postmyocardial infarction (MI) patients, are unknown. Therefore, HR and HRV (high frequency and total R-R interval variability) were evaluated at rest, during submaximal exercise, and during a 2-min coronary artery occlusion at rest and before and 3 mo after n-3 PUFA treatment in dogs with healed MI (n = 59). The dogs were randomly assigned to either placebo (1 g/day corn oil, n = 19) or n-3 PUFA supplement (docosahexaenoic acid + eicosapentaenoic acid ethyl esters; 1 g/day, n = 6; 2 g/day, n = 12; or 4 g/day, n = 22) groups. The treatment elicited significant (P < 0.01) dose-dependent increases in right atrial n-3 PUFA levels but dose-independent reductions in resting HR and increases in resting HRV. In contrast, n-3 PUFAs did not attenuate the large changes in HR or HRV induced by either the coronary occlusion or submaximal exercise. These data demonstrate that dietary n-3 PUFA decreased resting (i.e., preexercise or preocclusion) HR and increased resting HRV but did not alter the cardiac response to physiologic challenges.
authors: Dept. of Physiology and Cell Biology, Ohio State Univ., 304 Hamilton Hall, 1645 Neil Ave., Columbus, OH 43210-1218, USA. billman.1@osu.edu
authors: George E
authors: GE
authors: Billman
authors: William S
authors: WS
authors: Harris
mesh_terms: D000818:Animals; D019587:Dietary Supplements; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D004912:Erythrocytes / Q000187:drug effects; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D017202:Myocardial Ischemia / Q000503:physiopathology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D015525:Fatty Acids, Omega-3