Ischemic mitral regurgitation in patients with acute myocardial infarction.

AIM OF THE STUDY Echocardiographic evaluation of mitral regurgitation (MR) during the evolution of patients with acute myocardial infarction (MI). MATERIAL AND METHODS The study included 104 patients (73 males and 31 females), aged between 38-85, diagnosed with acute myocardial infarction (based on clinical, ECG and enzymatic evidences), in order to assess the MR (clinically--a new systolic murmur, and by echocardiography--the severity of MR). Echocardiography was performed upon admission and at 10-30 and 180 days after the onset of acute MI. The evaluation of MR was based on the following parameters: jet area, jet area indexed to left atrium, regurgitated volume, left atrial and left ventricular size, the evaluation of mitral valve apparatus in order to eliminate other possible causes of MR. RESULTS AND DISCUSSION MR was found in 35 patients from 104 diagnosed with acute MI, as follows: severe in 20 patients (jet area > 8 square cm, jet area indexed to left atrium > 40%, regurgitated volume > 30 mL) and mild in 15 patients (jet area < 4 square cm, jet area indexed to left atrium < 20%, regurgitant volume < 30 mL). In 30 patients MR was produced by the dilatation of mitral annulus (because of the evolution to ischemic dilatative cardiomyopathy), 5 patients developed left ventricular aneurysm; in 3 patients, MR was produced by chordae rupture and in 2 patients we diagnosed an ischemic prolapse of posterior mitral leaflet. In evolution all the patients developed symptoms and signs of heart failure, and 2 patients were referred to surgery. CONCLUSIONS The appearance of MR in the evolution of MI is an important sign of bad prognosis by its contribution to the appearance and/or to the worsening course of heart failure. Mechanisms of this MR are very complex based on the alteration of left ventricular geometry. Echocardiography plays an essential role in the early diagnosis of MR, estimating its severity, the mechanisms and also the prognosis.