NT-pro BNP (N-terminal pro-brain natriuretic peptide) is a bioactive endogenous peptide released from the ventricular myocardium during ventricular overload. It is synthesized from natriuretic peptide precursor C during hemodynamic stress, such as heart failure, where hypertrophied and dilated ventricles are observed.It is considered the "gold standard" for diagnosing and predicting heart failure at a very early stage, monitoring the effects of drug therapy, and differentiating dyspnea caused by heart failure from that caused by other conditions.NT-pro BNP levels in patients with heart failure correlate with the functional class according to the NYHA (New York Heart Association) classification. High NT-pro BNP levels are a poor prognostic indicator, while patients with levels below the lower reference limits for men and women are at low risk of developing complications such as left ventricular dysfunction, heart failure, or death.In this report, NT-pro BNP values were monitored in two patients admitted for treatment at the Cardiology Department of MC "St. Ivan Rilski" in Stara Zagora. The first patient was a 74-year-old man classified as NYHA functional class II, and the second was a 72-year-old woman classified as NYHA functional class III, both diagnosed with "Congestive heart failure." Upon admission, NT-pro BNP levels were significantly higher than the upper reference limits for their age. After treatment, the patients stabilized, and a decrease in NT-pro BNP concentration was observed upon discharge
