Patients requiring specialized cardiac care unit interventions (CCUIs) were identified from 414 consecutive admissions with known or suspected myocardial infarction (MI). Cardiac care unit interventions included administration of lidocaine hydrochloride, atropine sulfate, sodium nitroprusside, or vasopressors; Swan-Ganz or arterial catheterization; insertion of temporary pacemaker; and electroshock. Almost all interventions occurred in a high-risk group that had one or more of three findings: (1) ongoing chest pain, (2) pulmonary rales, or (3) one or more ventricular premature contractions (VPCs) on 12-lead ECG. Of 306 high-risk patients, 41% received at least one CCUI, and 4% died in the CCU. In contrast, of the 108 low-risk patients with none of the three criteria, only 6% received any CCUI, and none died in the CCU. This study suggests that patients who do not have ongoing pain, congestive heart failure, or VPCs when first evaluated have a very low risk of early complications and may not require intensive care.