Heart failure (HT) is a severe pathology, with a dramatic increasing occurrence in developped countries, due to the increasing mean age of populations and the longer survival of patients with chronic cardiac disease. This pathology is often associated with a general malnutrition process, considered as a very bad prognosis factor. Most of the myocardial pathological situations are associated with alterations in membrane composition, resulting from unbalanced homeostasis. The aims of this work was to evaluate the nutritional status in a model of heart failure obtained by ascending aortic banding in rats, and to determine the consequences on the membrane fatty acid composition of a dietary supplementation with DHA (docosahexaenoic acid C22 :6 n-3) a functionally important PUFA in the heart. Banded rats developed cardiac hypertrophy (+80%) and showed a significant increase in plasma BNP (+900%). The malnutrition is characterized in our model by a reduced food intake (-25%) associated with a 30% weight loss, a renal weight loss (-40%) a muscular atrophy, a lower muscle protein content and a severe dysfunction in the amino acid metabolism. No changes have been found in saturated and monounsaturated fatty acid (as % of total FA) but cardiac failure is associated with a significant decrease in membrane acid (LA. C18 :2 n-6), compensated by an increase of arachidonic acid (AA. C20 :4 n-6). Dietary supplementation of DHA have no effect on cardiac hypertrophy but prevented the general weight loss and gastrocnemius atrophy. DHA prevented LA decrease observed in cardiac membranes and AA was replaced by DHA. Functional investigations should now investigate the physiological interest of dietary supplementation of DHA.