Tolazoline-assisted Doppler echocardiography confirming normal pulmonary venous return in a neonate with severe persistent pulmonary hypertension.

In a critically ill neonate, pulsed and color-flow Doppler echocardiography was able to document normal pulmonary venous return after an intravenous dose of tolazoline hydrochloride. Differential diagnosis was between persistent pulmonary hypertension of the newborn and obstructed total anomalous pulmonary venous return. Once normal pulmonary venous return was clearly documented, all therapeutic efforts were directed at the infant's lung disease.