COLOR DOPPLER-ECHOCARDIOGRAPHIC EVALUATION OF TRICUSPID REGURGITATIONAND SYSTOLIC PULMONARY-ARTERY PRESSURE IN THE FULL-TERM AND PRETERM NEWBORN

Color Doppler echocardiography of tricuspid valve regurgitation (TR) i s a valid, noninvasive method of determining systolic pulmonary artery pressure (SPAP). In a prospective study the authors examined 56 healt hy full-term newborns (group I), 36 healthy preterm newborns (group II ), and 10 preterm newborns with severe respiratory distress syndrome r equiring surfactant replacement therapy (group III). Doppler studies w ere repeated until the transtricuspid gradient was <20 mm Hg. In 83.3% of children a reproducible spectral curve was recorded at least once. The authors estimated the transtricuspid gradient Delta p(RV-RA) by u sing the modified Bernoulli equation. Within the first twenty-four hou rs Delta p(RV-RA) was <20 mm Hg in 72.7%, 50%, and 25% of children wit h measurable TR in groups I, II, and III, respectively, increasing to 91.1%, 78.6%, and 55.6% within forty-eight hours. There was no signifi cant correlation between SPAP and gestational age, birth weight, mode of delivery, and ductal closing time. Continuous holosystolic envelope tracing of TR was recorded in 16.6%. In these patients Delta p(RV-RA) was measured markedly higher (mean of 30.1 mm Hg) than in the others (mean 17.3 mm Hg). The authors conclude that there is a high prevalenc e of TR in neonates, which allows estimation of SPAP in >80% of newbor ns without considerable impairment. Normalization of SPAP takes place within four days in most patients, but there is a delay in preterm inf ants with severe respiratory distress syndrome.