**4. Conclusion**

Natriuretic peptide levels are age dependent and show significant variability according to the type of the cardiac malformation and the actual hemodynamic condition. Recently, age related normal values have been established in the neonatal period and it allows detection of the congental heart disease in different age groups. Right sided hemodynamic ventricular stress is encountered with lower BNP values. Preoperative and postoperative application of natriuretic peptides provides a useful tool for the detection of postoperative complications. The new analyte, NT-proXNP seems to have promising characteristics, because it reflects the cardiac output changes earlier than the BNP, NT-proBNP assay.
