Myocardial rupture is a laceration of the walls of the heart chambers (ventricles or atria), of the papillary muscles or chordae tendineae, of the interatrial or interventricular septum, or of one of the valves of the heart. Myocardial rupture occurs after a serious sequela of an acute myocardial infarction (heart attack). It can also be caused by blunt and penetrating trauma, primary cardiac infection, and primary and secondary cardiac tumors.
Myocardial rupture is a relatively rare and usually fatal complication of myocardial infarction (MI). Early recognition of patients at greatest risk of myocardial rupture provides an opportunity for early intervention. Myocardial rupture was identified by autopsy (available in 138/589 patients dying within 30 days of index MI), echocardiography, direct surgical visualization, or presence of hemopericardium. Although rare, myocardial rupture accounted for nearly one fourth of all deaths within the first 30 days after high-risk MI, suggesting an estimated incidence of approximately 1% within the first 30 days. A number of clinical characteristics may identify post-myocardial infarction patients at higher risk of myocardial rupture.
Myocardial ruptures can be classified as one of three types: a) type I myocardial rupture is an abrupt slit-like tear that generally occurs within 24 hours of an acute myocardial infarction; b) type II is an erosion of the infarcted myocardium, which is suggestive of a slow tear of the dead myocardium. Type II ruptures typically occur more than 24 hours after the infarction occurred; c) type III ruptures are characterized by early aneurysm formation and subsequent rupture of the aneurysm.