Using echocardiography to study cardiac structure and function in a small series of patients with AIDS, abnormalities have been identified in from 25 to 75 percent of patients. All of these studies were retrospective; none was prospective with controls. Furthermore, all types of echocardiographic abnormalities have been described including the presence of pericardial fluid, mitral valve prolapse, chamber size abnormalities, and wall motion abnormalities. Although these abnormalities could have been due to infection with the HIV organism there were many other possible reasons for the echocardiographic abnormalities. Among AIDS patients there was a high incidence of intravenous drug and alcohol abuse, patients in whom cardiac abnormalities were common.