Effect of omega3 fatty acids on heart rate variability in depressed patients with coronary heart disease

Objective—Low intake of omega-3 fatty acids (FAs) is associated with depression and with low heart rate variability (HRV), and all three are associated with an increased risk of death in patients with coronary heart disease (CHD). The purpose of this study was to determine whether omega-3 FA increases the natural log of Very Low Frequency (lnVLF) power, an index of HRV, and reduces 24 hour heart rate (HR) in depressed patients with CHD. Methods—Thirty-six depressed patients with CHD randomized to receive 50 mgs of sertraline and two grams of omega-3/day, and 36 randomized to sertraline and a placebo, had 24 hour HRV measured at baseline and following 10 weeks of treatment. Results—There was a significant treatment X time interaction for covariate adjusted lnVLF (p=0.009), for mean 24 hour HR (p = 0.03), and for one minute resting HR (p = 0.02). The interaction was not significant for three other measures of HRV. LnVLF did not change over time in the omega-3 arm, but decreased in the placebo arm (p = 0.002), suggesting that omega-3 may have prevented or slowed deterioration in cardiac autonomic function. Conclusions—The effects of omega-3 FAs on lnVLF and HR, although modest, were detecte