Reperfusion therapy in inferior myocardial infarction

This review summarizes the multicenter trial results of reperfusion therapy for treatment of inferior myocardial infarction. Therapy with intracoronary streptokinase or intravenous recombinant tissue plasminogen activator (rt-PA) produced higher patency rates than did intravenous streptokinase. Reocclusion was more common when the right coronary artery was the infarct-related artery, irrespective of treatment strategy. Left ventricular ejection fraction was improved compared with that in control patients, especially when the time from symptom onset was brief or when patency rates were high. Enzymatic infarct size was reduced in treated patients. A trend toward mortality reduction in treated patients was found in four studies and was statistically significant in the Second International Study of Infarct Survival (ISIS-2) trial. Precordial ST segment depression in inferior myocardial infarction is associated with values for enzyme release, left ventricular ejection fraction and mortality similar to those in anterior infarction. Patients with inferior infarction who present within 6 h of symptom onset with precordial ST segment depression should be considered candidates for intravenous thrombolytic therapy with rt-PA; immediate cardiac catheterization and possible coronary angioplasty should be limited to those who are in hemodynamically unstable condition. Patients without precordial ST segment depression who present within 3 h of symptom onset and who do not have risk factors for bleeding should also be candidates for intravenous rt-PA therapy. The prognosis of other patients with inferior myocardial infarction is so good that the issue of thrombolytic therapy remains unsettled.