Treatment with F 16915 has no significant effect on body weight: 27.7±2.9 kg and 28.1±1.0 kg before surgery versus 29.2±3.4 kg and 28.8±1.7 kg after in the 1 and 5 g/day groups, respectively.?F 16915 administered at 5 g/day for 4 weeks significantly reduces the mean duration of Atrial fibrillation (AF) induced by burst pacing but has no significant effect at 1 g/day.?The duration of AF is significantly reduced from 989±111 s in the placebo group to 79±59 s in the presence of F 16915 at 5 g/day.?Treatment of 2 months with 100 mg/kg F 16915 also significantly reduces the infarct size.F 16915 is a docosahexaenoic acid derivative which can prevent heart failure-induced atrial fibrillation. Time-dependent changes in blood concentrations of total docosahexaenoic acid (DHA) and nicotinyl alcohol are followed after a single oral administration of F 16915 (300 mg/kg) to male rats.