Whenever the coronary flow is inadequate to provide enough oxygen to meet the energy demands of the tissue, the heart becomes ischemic. Manifestations of myocardial ischemia include depression in contractile activity, changes in metabolic pattern, abnormalities in ultrastructure, and alterations in membrane potential. Ischemic changes during the early phase are reversible but as the period of ischemia is extended, the injury becomes irreversible. The transition from reversible to irreversible ischemic injury is usually associated with some membrane defects. It is worthwhile to consider that...