title: Dietary fish and n-3 fatty acid intake and cardiac electrocardiographic parameters in humans.
abstract: OBJECTIVE
  We evaluated the association between dietary fish intake and several cardiac electrocardiographic parameters in humans relevant to arrhythmic risk.
  
  
  BACKGROUND
  Fish consumption may reduce the incidence of sudden death and atrial fibrillation, possibly related to anti-arrhythmic effects.
  
  
  METHODS
  In a population-based study of 5,096 men and women, we evaluated cross-sectional associations between usual dietary fish intake and electrocardiographic measures of heart rate, atrioventricular conduction (PR interval), ventricular repolarization (QT interval), and ventricular conduction (QRS interval). Multivariate models were adjusted for age, gender, race, education, smoking, body mass index, diabetes, coronary heart disease, physical activity, and intakes of beef or pork, fried fish, fruits, vegetables, alcohol, and total calories.
  
  
  RESULTS
  Consumption of tuna or other broiled or baked fish (comparing the highest to the lowest category of intake) was associated with lower heart rate (-3.2 beats/min, 95% confidence interval [CI] = 1.3 to 5.1; p trend <0.001), slower atrioventricular conduction (PR interval +7.2 ms, 95% CI = 1.4 to 12.9; p trend = 0.03), and substantially lower likelihood of prolonged QT (relative risk = 0.50, 95% CI = 0.27 to 0.95; p trend = 0.03). Tuna/other fish intake was not associated with ventricular conduction (p = 0.60). Findings were similar for estimated intake of marine n-3 fatty acids: a 1 g/day higher intake was associated with 2.3 beats/min lower heart rate (95% CI = 0.9 to 3.7), 7.6 ms longer PR interval (95% CI = 3.3 to 11.9), and 46% lower likelihood of prolonged QT (relative risk = 0.54, 95% CI = 0.33 to 0.88).
  
  
  CONCLUSIONS
  These findings in this large, population-based study suggest that dietary fish intake is associated with cardiac electrophysiology in humans, including heart rate, atrioventricular conduction, and ventricular repolarization, with potential implications for arrhythmic risk.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA. dmozaffa@hsph.harvard.edu
authors.forename: Dariush
authors.initials: D
authors.lastname: Mozaffarian
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Prineas
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
authors.forename: David S
authors.initials: DS
authors.lastname: Siscovick
mesh_terms: D000368:Aged; D000818:Animals; D001283:Atrioventricular Node / Q000502:physiology; D003430:Cross-Sectional Studies; D004032:Diet; D004562:Electrocardiography; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D005399:Fishes; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D016276:Ventricular Function
chemical_list: D015525:Fatty Acids, Omega-3