[Biventricular infarctions]

Abstract

Posterior biventricular myocardial infarctions are more frequent than anterior ones. Unipolar right and high abdominal leads are necessary for the diagnosis. These supplementary leads are dependable, can be repeated as many times as necessary and show the evolution from signs of injury to those of inactivable tissue (Q waves of 0.04 sec or more). This information on evolution increases the diagnostic value of the electrocardiogram since signs of an injury current can be observed in other conditions as well. The diagnosis of right ventricular infarction can be established even in the presence of RBBB, but the differential diagnosis with acute cor pulmonale must be established on clinical as well on laboratory basis. The signs of an inactivable zone of the free right ventricular wall are more frequently observed in posterior biventricular infarctions than in the anterior ones. In the latter, signs of subepicardial injury are more accentuated in right thoracic leads than in V2 and V3, which indicate anterior right ventricular involvement. The same signs are also observed in experimental studies. A review of medical literature concerning the prognosis and evolution of biventricular myocardial infarctions is presented.