UNLABELLED Left ventricular remodeling is a complex pathologic process of progressive dilatation, leading to dysfunction and heart failure in patients with acute myocardial infarction. The aim of our study was to determine and evaluate biochemical markers, reflecting cardiac remodeling process in the patients with the first myocardial infarction and to compare those markers with clinical characteristics of left ventricular remodeling. MATERIAL AND METHODS Concentrations of brain natriuretic peptide and markers of myocardial necrosis were measured on 1st , 2nd and 7th day after the onset of the first acute myocardial infarction, as well as after 3 and 6 months in 30 patients. Parameters of left ventricular remodeling were determined by echocardiographic investigation, which was performed in the acute phase and after 3 and 6 months. RESULTS Brain natriuretic peptide concentration was found to be related to the left ventricular geometry in the acute phase: brain natriuretic peptide peak level was lower in the patients with the normal left ventricular geometry than in the patients with the changed left ventricular geometry (140.6+/-63.3 pg/ml vs. 385.7+/-283.9, p<0.05). Brain natriuretic peptide concentration in the acute phase was higher in the patients who had increased left ventricular end diastolic diameter through 6-month period (348.9+/-309.4 pg/ml vs. 145.1+/-109.6 pg/ml, p<0.05). Higher troponin I (58.8+/-33.6 ng/ml vs. 30.9+/-31.3 ng/ml, p<0.05) and troponin T (4.5+/-2.2 ng/ml vs. 1.9+/-2.0 ng/ml, p<0.05) levels were also associated with left ventricular dilatation through 6 months after myocardial infarction. CONCLUSIONS Brain natriuretic peptide level in acute phase of myocardial infarction is related to the left ventricular geometry changes and remodeling. Brain natriuretic peptide together with other cardiac markers might be useful in predicting subsequent cardiac function.