During myocardial ischemia, oxidative metabolism is reduced and fatty acids and triglycerides accumulate within the myocardial cell. The fatty acids and related substances, such as fatty acylcarnitines, are amphophilic and can lead to cell membrane destruction. Magnetic resonance methods can assess the concentration of lipids (generally triglycerides) within the myocardium. The observation of lipids within the myocardium is postulated to indicate viability. Various pharmacological interventions are used to evaluate their effect on myocardial lipid accumulation in control and during myocardial ischemic insults. Surface coils placed on the epicardium are used to interrogate the myocardial lipid content in a 4.7T Bruker Biospec 40cm bore system in canine models. It is anticipated that in the last years of this RO1, patients with MI, both reperfused and non-reperfused, will be studied in the 4.1T MR system to determine the relationship between myocardial lipid content and high energy phosphate metabolism.