We analyzed tricuspid insufficiency noninvasively using cross-sectional and continuous wave Doppler echocardiography in 49 newborn infants free of structural cardiac and pulmonary disease. In 41(83.6%) of the cases, mild insufficiency was detected using the continuous wave Doppler technique. All the infants with valvar insufficiency had normal electrocardiographic tracings and, in 25 (61%) of them, there was no audible murmur. We detected transient ductal patency in five (12.1%). The ratio of right ventricular preejection period to ventricular ejection time was in the normal ranges (below 0.05) in 39 (95.1%) of the neonates. Of the 30 cases who underwent continued surveillance over a mean period of 37.9 days, the incompetence disappeared in 15 (50%). Our findings show that, in neonates, the lack of a murmur does not eliminate the possibility of neonatal tricuspid incompetence. Furthermore, abnormalities such as postnatal transient pulmonary hypertension, fetal closure of the arterial duct and perinatal asphyxia cannot readily explain the finding of tricuspid incompetence.
