@article {910, title = {Dietary fish and n-3 fatty acid intake and cardiac electrocardiographic parameters in humans.}, journal = {J Am Coll Cardiol}, volume = {48}, year = {2006}, month = {2006 Aug 01}, pages = {478-84}, abstract = {

OBJECTIVES: 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.

}, keywords = {Aged, Animals, Atrioventricular Node, Cross-Sectional Studies, Diet, Electrocardiography, Fatty Acids, Omega-3, Female, Fishes, Heart, Heart Rate, Humans, Male, Ventricular Function}, issn = {1558-3597}, doi = {10.1016/j.jacc.2006.03.048}, author = {Mozaffarian, Dariush and Prineas, Ronald J and Stein, Phyllis K and Siscovick, David S} } @article {1020, title = {Dietary fish and omega-3 fatty acid consumption and heart rate variability in US adults.}, journal = {Circulation}, volume = {117}, year = {2008}, month = {2008 Mar 04}, pages = {1130-7}, abstract = {

BACKGROUND: Fish and omega-3 fatty acid consumption reduce risk of cardiac death, but mechanisms are not well established. Heart rate variability (HRV) predicts cardiac death and reflects specific electrophysiological pathways and influences. We hypothesized that habitual consumption of fish and marine omega-3 fatty acids would be associated with more favorable HRV, elucidating electrophysiological influences and supporting effects on clinical risk.

METHODS AND RESULTS: In a population-based cohort of older US adults, we evaluated cross-sectional associations of usual dietary fish and omega-3 consumption during the prior year and ECG-derived (n=4263) and 24-hour Holter monitor-derived (n=1152) HRV. After multivariable adjustment, consumption of tuna or other broiled/baked fish was associated with specific HRV components, including indices suggesting greater vagal predominance and moderated baroreceptor responses (eg, higher root mean square successive differences of normal-to-normal intervals [P=0.001]; higher normalized high-frequency power [P=0.008]; and lower low-frequency/high-frequency ratio [P=0.03]) and less erratic sinoatrial node firing (eg, lower Poincar{\'e} ratio [P=0.02] and higher short-term fractal scaling exponent [P=0.005]) but not measures of circadian fluctuations (eg, 24-hour standard deviation of normal-to-normal intervals). Findings were similar for estimated dietary consumption of marine omega-3 fatty acids. For magnitudes of observed differences in HRV comparing the highest to lowest category of fish intake, differences in relative risk of cardiac death during 10.8 years of follow-up ranged from 1.1\% (for difference in standard deviation of normal-to-normal intervals) to 5.9\% and 8.4\% (for differences in Poincar{\'e} ratio and short-term fractal scaling exponent) lower risk.

CONCLUSIONS: Habitual tuna/other fish and marine omega-3 consumption are associated with specific HRV components in older adults, particularly indices of vagal activity, baroreceptor responses, and sinoatrial node function. Cellular mechanisms and implications for clinical risk deserve further investigation.

}, keywords = {Aged, Aged, 80 and over, Animals, Cardiovascular Diseases, Cohort Studies, Cross-Sectional Studies, Electrocardiography, Fatty Acids, Omega-3, Female, Fishes, Heart Rate, Humans, Male, Risk Factors, Seafood, Tuna, United States}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.107.732826}, author = {Mozaffarian, Dariush and Stein, Phyllis K and Prineas, Ronald J and Siscovick, David S} }