Application of determined NT-proBNP in physical standardized exercise.

UNLABELLED Natriuretic peptides can be used as markers of heart failure, its severity and also in the differential diagnosis of dyspnea. Moreover, the dynamics of natriuretic peptides in physical standardized exercise may be used in the assessment of latent heart failure. AIM OF THE STUDY Can determination of NT-proBNP be used in the diagnosis of exercise-induced ischemia or latent heart failure? 18 probands (10 men, 8 women) under study were risk persons with unspecified ECG, without signs of manifest heart failure. They were subjected to ergometric bike exercises up to the subjective maximum, SPECT myocardium with estimated ejection fraction of the left ventricle at peak ergometric exercise. The following parameters were followed-up: a) before ergometric exercise: NT-proBNP, CRP, TNF-alpha, Hb, Htc, lactate b) at subjective maximum: NT-proBNP, Hb, Htc, lactate c) 30 min after stopping the exercise: NT-proBNP d) 60 min after stopping the exercise: NT-proBNP. The volume blood changes were taken into account (estimation from the dynamics of Htc, Hb with calculation of metabolic changes of NT-proBNP). To evaluate the dynamics of NT-proBNP, the group was divided into subgroups according to the results obtained in ergometric exercises. RESULTS initial values of NT-proBNP within normal limits (< 59 pmol/l, 500 ng/l) in 94%, the submaximal pulse rate was reached in 94%, ischemic changes in ECG were observed in 59%, typical clinical signs of heart ischemia were recorded in 35%. Signs of heart dysfunction according to SPECT were found in 47% and ischemic symptoms were observed in 43%. In general, the plasmatic volume decreased by 24% at maximal exercise. Lactate concentration in the plasma increased in all cases. Conversion of NT-proBNP into volume blood changes revealed that increased NT-proBNP occurred only in 22%. Differences between NT-proBNP before exercises and at maximal exercise prior and after correction into volume blood changes were statistically insignificant. 30 and 60 min after the exercise, no significant differences were found in NT-proBNP concentrations. Dividing into subgroups according to the results of ergometric exercises, showed no significant differences in NT-proBNP concentrations. Dynamics of NT-proBNP changes during and after ergometric exercises cannot be used for the diagnosis of exercise-induced heart failure. The high stability of NT-proBNP related to physical activity was confirmed.