Abstract 1051 Poster Session IV, Tuesday, 5/4 (poster 214)

We compared the use of agitated normal saline solution contrast echocardiography, and color flow Doppler in the detection of right to left shunt at atrial level in infants. Forty-four newborn infants at 1 to 10 days of age, and clinical diagnosis of pulmonary hypertension, underwent transthoracic echocardiographic examination to rule-out intracardiac right to left shunt. Forty-one had normal intracardiac anatomy, 3 infants were excluded because of the finding of significant heart disease. From the 41 patients studied, saline contrast echocardiography revealed right to left shunt at atrial level in 15; color Doppler demonstrated bi-directional or right to left shunt in 8 of the 15 (53%). From the 7 patients in whom color Doppler failed to identify the right to left shunt, 5 were on high frequency ventilation. Contrast echocardiography never failed to demonstrate a right to left shunt detected by color Doppler.

CONCLUSION: Color Doppler failed to detect right to left shunt at the atrial level in a significant number of cases; agitated saline contrast echocardiography should be used in all newborn infants with normal intracardiac anatomy in whom intracardiac shunt at the atrial level needs to be ruled out. Low velocity right to left shunt at the atrial level, poor imaging from lung disease, and interference from the high frequency ventilator, may be some of the causes for the failure to detect the shunt by color Doppler.