B-type natriuretic peptide (BNP) is a hormone released by ventricular cardiomyocytes in response to hemodynamic stress and is responsible for numerous physiological effects. Determining the seric level of this hormone plays an important role in the therapeutic approach of the patient. BNP dosing in the blood helps establish the diagnosis of heart failure, assess the severity of the heart failure, make the therapeutic decision, important prognostic value, monitor the effectiveness of the treatment, important role in the population screening programs. The purpose of the research is to study the NT-proBNP values in a group of hypertensive patients with heart failure NYHA II-IV, and its relation with the patient's age and sex, the ejection fraction (EF) and other left ventricular echocardiographic data, elucidating the link between rhythm cardiac, blood O2 saturation and NT- proBNP. The study included 50 hypertensive patients with NYHA II-IV heart failure, admitted to hospital „Sfânta Treime”, from Chișinău. Depending on the value of NT-proBNP patients were divided into two groups. The first group included 30 patients, mean value of NT- proBNP 2884.53pg/ml, mean FE 51.29%, mean left ventricular (DTD) telediastolic diameter 51.41mm. In group 2 were included 20 patients with mean NT-proBNP value 201.95pg / ml, mean FE 56.54% and mean DTD 49.81mm. It has been observed that NT- proBNP values were higher in women. It is suggested a dependence of the NT-proBNP age values - there is a physiological increase of the normal NT-proBNP values, as the age increases. The value of the EF is inversely proportional to the numerical value of NT- proBNP, thus in the first group the average was 51.29%, and in the second group - 56.54%. The NT-proBNP values do not discriminate patients with reduced ejection fraction or reduced DTD with heart failure II-IV NYHA. Enlargement of the left atrium is a sensitive parameter, and has a good correlation with the increase of NT-proBNP values. There is a very high incidence of diastolic dysfunction, associated with high levels of NT-proBNP.