Acute hemodynamic effects of intravenous fat emulsion in dogs.

An intravenous infusion of Intralipid-10% was observed to exert a negative inotropic effect on left ventricular performance in a canine isovolumetric left heart preparation. There was no effect on diastolic compliance, however. Intravenous fat emulsion also produced significant decreases in systemic vascular resistance. The mechanism of these actions has not been elucidated, but it is postulated that free fatty acid (FFA) components or their metabolites directly affect the contractile properties of both myocardium and smooth muscle. These results suggest that until suitable clinical studies can be obtained, caution should be exercised in administering intravenous fat emulsions, particularly at maximum rates of infusion or in conjunction with sodium heparin in patients with known cardiac dysfunction.