Single Doppler detection of left to right shunt through the ductus arteriosus.

Forty-two infants and children were examined with unguided continuous and pulsed Doppler echocardiography before and/or after surgical closure of ductus arteriosus or in connection with cardiac catheterization. Presence or absence of diastolic reverse flow in the main pulmonary artery was evaluated for sensitivity and specificity to detect left to right ductus shunt. Diastolic reverse flow was detected in 15 of 16 patients with such a shunt and in 3 of 38 patients without a left to right ductus shunt. This corresponds to 94% sensitivity and 92% specificity. It is concluded that the accuracy of a single Doppler system in diagnosing patent ductus arteriosus is comparable to the results obtained with a Doppler interfaced to M-mode or cross-sectional echocardiography.