Table 1.

Demographic breakdown of the dataset (N = 265).

Hospitals:
− Centre 1	3 (1%)
− Centre 2	262 (99%)
Sex:
− Males	137 (52%)
Gestational age [weeks]:	Median 39, IQR: 38–40
− Less than 37 weeks (preterm)	23 (9%)
− 37 weeks or more (term)	242 (91%)
Postnatal age [hours]	Median 48, IQR: 30–64
− Less than 24 h	29 (11%)
− From 24 to 48 h	95 (36%)
− From 48 to 72 h	87 (33%)
− More than 72 h	54 (20%)
Diagnostics
− Healthy	137 (52%)
− Patent Ductus Arteriosus (PDA)	89 (33%)
− Other Congenital Heart Defects (CHD)	39 (15%)
− Ventriculoseptal defect	28 (71% of all CHD)
− Partial anomaly of pulmonary veins	6 (15% of all CHD)
− Congenital defect of trilateral valve development	2 (5% of all CHD)
− Atrioseptal defect	1 (3% of all CHD)
− Congenital aortic valve stenosis	1 (3% of all CHD)
− Tetralogy of Fallot	1 (3% of all CHD)
Total number of patients	265