NPPB and hydrops fetalis: Airway obstruction decreases expiratory flow rates and causes lung hyperinflation, which is associated with decreased cardiac function and may increase NT-proBNP.6 NT-proBNP may also be elevated due to pulmonary hypertension and right ventricular dysfunction caused by pulmonary arterial pressure overload.34, 35 Early right ventricular structural abnormalities could ultimately lead to a deterioration of left ventricular function and clinical HF.