Intramyocardial Dissecting Hematoma and Postinfarction Cardiac Rupture

Abstract

Potentially fatal cardiac rupture is a complication of myocardial infarction (MI), which can appear in the first hours of the acute event and during the course of the first week. The intramyocardial dissecting hematoma might appear as a component of the rupture during the evolution process. The description of the myocardium as a helical muscular band facilitates the explanation of the fiber dissection. With echocardiography, it is possible to diagnose intramyocardial dissecting hematomas (IDH), determine its location, progression, potential complications, and in some cases its reabsorption. It is necessary to search for neocavitations in the infarcted myocardium and identify the intramyocardial edge that surrounds the defect, as well as the flow inside the myocardial dissection, the pathway of the dissection, and its communication with ventricular cavities, and also to look for the complete or partial reabsorption of the cavitary image. The greater the myocardial dissection is, the worse the prognosis. If the dissecting hematoma is confined to the apical segments, it is more likely to reabsorb spontaneously. Tissue characterization with magnetic resonance during an acute myocardial infarction allows identification of reperfusion injuries with altered microcirculation and intramyocardial hemorrhage (IMH). It is necessary to search for IMH in reperfused patients with ventricular arrhythmias, stunned myocardium, and no reflow. These patients may develop an increased stiffness in the infarcted wall and a major likelihood to develop a parietal rupture. Everything seems to indicate that we are facing the same physiopathological process which can be characterized by 2 complementary imaging methods, echocardiography and magnetic resonance.