Materials and Methods: In this analytical-descriptive study, 30 infants and children with respiratory distress, recurrent pneumonias, failure to thrive and had a murmur in their physical examinations and a cardiomegaly on the chest x-ray was selected. Patients have one of ventricular septal defect (VSD), atrial septal defect (ASD) or pulmonary duct artery (PDA) in echocardiography. The BNP serum level measured and compared to the quantity of the left to right shunt and systolic pulmonary pressure detected through evaluation of tricuspid regurgitation (TR) by echocardiography. Velocity time integral (VTI) measured by doppler echocardiography at the pulmonary and aortic valves for VSD and ASD, mitral and tricuspid valves for PDA, the Qp/Qs ratio was detected to determine if there was any significant relationship between the former and the two latter.

Results: There was a significant relationship between level of pro-BNP and the quantity of the shunt in the patients with VSD, ASD and PDA (P = 0.01). A positive correlation between BNP serum level and Qp/Qs ratio in all the patients. There was significant relationship between pro-BNP level and the systolic pulmonary pressure (P < 0.001). The cut-off point of pro-BNP demonstrating a Qp/Qs ratio more than 1.5 was measured at the level of 36.95 pg/mL, with a sensitivity and specificity of 100% and 83.3%, respectively.

Conclusion: In patients whom PAH pressure cannot be measured for any reason, measure BNP serum can be useful.