**3.5 Pediatric cardiac population–follow-up period**

Pediatric cardiac population follow-up period Pediatric patients with simple cardiac lesions after corrective surgery show a marked reduction in BNP and NT-proBNP levels compared to the preoperative period. The same is true after catheter interventions, like closure of atrial septal defect or closure of ductus arteriosus. In patients with residual defects, like pulmonary stenosis or pulmonary arterial hypertension, serial measurements of BNP or NTproBNP levels provide a useful, easy and non-invasive tool for follow-up and it can be used for quantification of the disease severity. During the follow-up of cardiac transplant patients rejection can be detected by increase of BNP levels.
