Current concepts in clinical therapeutics: acute myocardial infarction.

The epidemiology and etiology, pathophysiology, diagnosis, clinical presentation, complications, and treatment of acute myocardial infarction (AMI) are reviewed. Major risk factors for AMI include age, sex (men greater than women), family history, race, hyperlipidemia, hypertension, cigarette smoking, diabetes mellitus, and diet. AMI occurs when there is a prolonged decrease in oxygen supply to the myocardium caused by coronary thrombosis or coronary vascular spasm. Traditional drug treatment of uncomplicated AMI includes oxygen, laxatives, and analgesics. For analgesia, narcotic agonists are generally preferred, although intravenous nitroglycerin is of value for both reducing infarct size and relieving pain. Fibrinolytic therapy is also indicated in these patients. Low-dose heparin should be initiated on admission to the hospital. Beta-adrenergic blocking agents have proven useful in reducing the incidence of ventricular fibrillation and sudden death. Antiplatelet agents may also be used to decrease long-term mortality. Recent studies have focused on reduction of infarct size using agents such as beta blockers, calcium-channel blockers, nitroglycerin, and thrombolytics. Revascularization procedures are required in some patients to re-establish adequate coronary perfusion. Most patients who survive AMI initially have a relatively uncomplicated clinical course. An increasing number of therapeutic interventions are available for acute and chronic treatment of AMI.