Pulsatile flow changes in the anterior cerebral arteries in infants with patent ductus arteriosus: measured with Doppler technique.

Cerebral hemodynamics were measured, using the Doppler ultrasound technique (directed toward anterior cerebral artery through the anterior fontanel), in 6 patent ductus arteriosus (PDA) patients with large left to right shunt and in 32 neonates before and just following functional closure of ductus arteriosus. PDA was confirmed by color echocardiogram and Doppler flow study. All 6 sick babies had prominent retrograde flow in the descending aorta during diastole. The value of pulsatility index (PI) derived from the components of peak systolic and end--diastolic frequency, was calculated. An obvious higher PI with simultaneous decrease in diastolic Doppler frequency in sick babies (PI = 0.89 +/- 0.05) were detected. On the contrary, the PI valves in the presence of opening of the ductus (PI = 0.65 +/- 0.07) in normal newborn infants didn't differ significantly with those just following functional closure (PI = 0.63 +/- 0.05). These data suggested that PDA might result in the physiologic consequence of ischemic cerebral injury if large left to right shunt occurred.