The mechanism(s) underlying these beneficial effects remains to be elucidated and will be critical in fully exhausting the therapeutic benefits of Omega 3 in CHF. We have recently demonstrated that lipid oxidation during acute exercise is altered in patients with CHF 12 and that the degree of this alteration carries prognostic significance. It is conceivable that Omega 3 modulates lipid oxidation during exercise and thereby favorably effect outcome. Accordingly we propose to study the effect of Omega 3 on lipid oxidation during exercise in CHF. We will further examine VO2 and endothelial function at present the principal surrogate markers for survival in CHF 13.