<prompt> A 60-year-old male patient on aspirin, nitrates, and a beta blocker, being followed for chronic stable angina, presents to the ER with a history of two to three episodes of more severe and long-lasting anginal chest pain each day over the past 3 days. His ECG and cardiac enzymes are normal. The best course of action of the following is toAdmit the patient and begin intravenous digoxinAdmit the patient and begin intravenous heparinAdmit the patient and give prophylactic thrombolytic therapyAdmit the patient for observation with no change in medication  <response>: This patient presents with unstable angina, a change from the previous chronic stable state in that chest pain has become more frequent and more severe. Intravenous heparin is indicated. Subcutaneous administration of low-molecular-weight heparin such as enoxaparin is an alternative. There is no role for digoxin, as this may increase myocardial oxygen consumption and exacerbate the situation. Thrombolytic therapy is reserved for the treatment, typically within 6 h, of ECG-documented myocardial infarction and does not reduce cardiac events in the setting of unstable angina. A more aggressive approach is early interventional cardiac catheterization with angioplasty andor stent placement, possibly in conjunction with glycoprotein IIbIIIa inhibitors. 