A method of treating patients in need of treatment for a cardiac disorder has been found which comprises administering to the patient a seven carbon fatty acid compound or derivative thereof, wherein the compound or derivative thereof is able to readily enter the mitochondrion without special transport enzymes. A dietary formulation suitable for treatment of heart tissue in cardiac or surgical patients has been found which comprises a seven-carbon fatty acid chain, wherein the seven-carbon fatty acid chain is characterized by the ability to transverse the inner mitochondrial membrane by a transport mechanism which does not require carnitine palmitoyltransferase I, carnitine palmitoyltransferase II, or carnitine/acylcarnitine translocase and the ability to undergo mitochondrial .beta.-oxidation, and wherein the compound is selected from the group consisting of n-heptanoic acid or a derivative thereof, a triglyceride comprising n-heptanoic acid or a derivative thereof, and triheptanoin or a derivative thereof.