Cerebral artery flow velocity acceleration and deceleration characteristics in newborn infants

To evaluate maturational differences in the cerebral artery blood flow velocity characteristics, we measured the middle cerebral (MCA) and basilar artery blood flow velocity and time intervals using a real-time imaging pulsed Doppler system in 39 preterm and 25 term infants. Preterm MCA and basilar artery mean Doppler spectral area under the curve were approximately 22 and 25% lower than the corresponding term values, with a significant increase during gestation as revealed by regression models. Paradoxically, the mean MCA systolic acceleration and deceleration slopes were approximately 28 and 18% higher in preterm than in term infants: acceleration 701.2 +/- 160 cm/s2 versus 546.4 +/- 156.5/s2 (p less than 0.005), and deceleration 222.2 +/- 71.6 cm/s2 versus 188.2 +/- 52.2 cm/s2 (p less than 0.05), respectively. Similarly, acceleration and deceleration pressure half times for MCA were about 15 and 18% shorter in the preterm (p less than 0.01 and less than 0.005). Multiple regression models controlling for velocity and frequency terms revealed an inverse relationship between gestational age and MCA acceleration (p less than 0.005), and a positive relationship between gestational age and MCA acceleration pressure half times (p less than 0.02). In preterm infants the MCA specific index of pulsatility was about 32% higher (p less than 0.05) than in the term, which was also inversely related to gestational age in a regression model controlling for velocity terms (p less than 0.02). However, the basilar artery acceleration and deceleration slopes were not significantly different between term and preterm groups, nor showed a significant gestational age effect in the multiple regression models.(ABSTRACT TRUNCATED AT 250 WORDS)