[The influence of thrombolytic therapy on selected parameters of left ventricular function in acute myocardial infarction]

Abstract

Our study aimed to evaluate the influence of thrombolytic therapy on some left ventricle (LV) function parameters in patients with acute myocardial infarction. The study was performed on 44 pts admitted to hospital due to acute myocardial infarction. The patients were divided into two groups: I group--30 pts (26 male, 4 female) at average age 57 +/- 10 who were treated with tissue plasminogen activator (t-PA) routinely and II group--14 pts (9 male, 5 female) at average age 62 +/- 10 in whom thrombolytic therapy was contraindicated for various reasons. Transthoracic echocardiography was performed just before treatment (0), 3.5 hours after the onset of drug administration (2 hours after the end of t-PA injection) (1) and on the 10th day of hospitalization (2). Control group consisted of 16 clinically healthy individuals (12 male, 4 female) at average age 54 +/- 9. The following parameters were evaluated: DT-E--wave of early diastolic transmitral flow deceleration time, IVRT--isovolumic relaxation time, E/A--early/atrial peak flow velocity ratio of transmitral flow, LATEF%--left atrial total emptying fraction, EF--left ventricle ejection fraction. In patients with acute myocardial infarction shortening of DT, prolongation of IVRT, lower E/A ratio and decrease of LATEF% compared to controls were observed. In group I EF was less than in clinically healthy individuals. E/A ratio was higher in pts from group I than from group II. In patients treated with t-PA 2 hours after treatment as well as on the 10th day significant prolongation of DT, shortening of IVRT and increase of LATEF% were observed. These changes were accompanied by the increase of EF. In patients with acute myocardial infarction not treated with t-PA significant increase in E/A ratio and EF on 10th day were observed. On the basis of the results were conclude: In patients with acute myocardial infarction LV diastolic function and with unproper relaxation as well as unproper compliance of LV myocardium is present. In patients with thrombolytic therapy LV filling pattern improves just two hours after t-PA administration (DT prolongation, IVRT shortening, LATEF% increase). Such tendency remains on the 10th day after treatment. In patients without thrombolytic therapy slight improvement occurs no sooner than on the 10th day of the MI.