After undergoing repair of a left indirect inguinal hernia, a 72-year-old obese man is admitted to the emergency department with severe retrosternal pain of 1-hours duration. The pain radiates to the medial aspect of the left hand. The ECG shows Q waves and an elevated ST-segment. A diagnosis of acute MI is established 1 hour after admission. Immediate management should include which of the following?

Thrombolytic therapy intravenously with streptokinase, urokinase, or tPA is indicated in most patients with MI presenting early for treatment. This therapy, however, is effective only if initiated within 6 hours after the onset of pain in patients with acute MI. These drugs are fibrinogenolytic, and aspirin and heparin are frequently included in the anticoagulant protocol. Reperfusion rates of 60% can be anticipated; reocclusion rates of 15% usually occur. Vitamin K is not indicated, because it would increase the coagulability of blood. If a diuretic, such as hydrochlorothiazide, 25-50 mg/d is indicated to treat milder hypertension, hypokalemia must be avoided.