The mechanical complications of acute myocardial infarction: echocardiographic visualizations

Background: Majority of the clinical experiences, especially by echocardiographic evaluations, was merely limited to sporadic cases as reported in the literature. Methods: Between January 2004 and July 2008, 19 patients (9 males, 10 females; mean age 71.7 +/- 8.2 years; range 56 to 91 years) were referred to our clinic for surgical treatment of the mechanical complications of acute myocardial infarction. Eight (42.1%) patients had free wall rupture (FWR). One of them developed FWR after completion of anesthesia before being scrubbed on the operating table for a scheduled coronary artery bypass grafting surgery. Five (26.3%) had papillary muscle rupture, five (26.3%) had ventricular septal rupture (VSR), and one (5.3%) had double structure rupture (VSR + FWR). Results: Seven of the eight FWR patients had their echocardiographic information archived. At the onset of these mechanical complications, six (85.7%) patients presented with pericardial tamponade on echocardiography, and one (14.3%) with moderate pericardial effusion. Posterior mitral leaflet flail was noted in all four patients with a posteromedial papillary muscle rupture on echocardiography. The flow across the flail mitral valve was mosaic but not eccentric in two patients, and neither mosaic nor eccentric in two patients. Large erratic movement of the ruptured papillary muscle and the swirling papillary muscle head could be observed in the left atrium in the patient with a complete ruptured papillary muscle. Anterior mitral leaflet flail with eccentric mosaic flow was noted on echocardiography in the only patient with an anterolateral papillary muscle rupture. Four (80%) of the five ventricular septal ruptures were located in the anterior wall, and one (20%) was anteriolateral. The defect and the shunt flow were observed in all five (100%) patients on echocardiography. Two of them (40%) had moderate pericardial effusion. Conclusion: Echocardiography is a reliable diagnostic tool for diagnosing the mechanical complications of acute myocardial infarction in terms of the location and dimension, and is essential for the decision-making on the treatment strategy and postoperative follow-up.