OBJECTIVE: To determine left ventricular isovolumic relaxation time (LV IRT) in normally developing and growth restricted fetuses (FGR) as an indicator of fetal cardiac afterload and neonatal systolic blood pressure. STUDY DESIGN: A prospective longitudinal study in 124 normally developing and 47 growth restricted fetuses (FGR). LV IRT, fetal heart rate (FHR) and umbilical artery pulsatility index (PI) were determined at 2-3 week intervals starting at 22-26 weeks of gestation until delivery. Renin and angiotensin I levels were measured by radioimmunoassay in umbilical venous blood after delivery. Systolic blood pressure was measured at day 1 and day 5 of postnatal life. To evaluate the association between LV IRT, gestational age and FHR, bivariate regression analyses were performed. RESULTS: Mean LV IRT (62+/-8 ms) was 29 percent longer in FGR as compared to the normal subset (47+/-6 ms) at all gestational ages (p<0.001). Mean postnatal active plasma renin level (7.78+/-S.D. 1.03 ng/ml) and postnatal angiotensin I level (4.21+/-0.70 ng/ml) in the FGR subset were significantly higher (p<0.001) than in the normal subset (4.81+/-1.04 ng/ml, renin and 2.69+/-0.44 ng/ml, angiotensin I). There was a significant difference (p<0.01) in systolic blood pressure between the two subsets on postnatal day 1 (FGR 52+/-6 mmHg vs. normal 46+/-4 mmHg) and day 5 (FGR 76+/-5 mmHg vs. normal 60+/-6 mmHg). CONCLUSION: Left ventricular isovolumic relaxation time may act as a sensitive index of increased arterial afterload in the growth retarded fetus and may herald raised systolic blood pressure in the early neonatal period.
OBJECTIVE: To determine left ventricular isovolumic relaxation time (LV IRT) in normally developing and growth restricted fetuses (FGR) as an indicator of fetal cardiac afterload and neonatal systolic blood pressure. STUDY DESIGN: A prospective longitudinal study in 124 normally developing and 47 growth restricted fetuses (FGR). LV IRT, fetal heart rate (FHR) and umbilical artery pulsatility index (PI) were determined at 2-3 week intervals starting at 22-26 weeks of gestation until delivery. Renin and angiotensin I levels were measured by radioimmunoassay in umbilical venous blood after delivery. Systolic blood pressure was measured at day 1 and day 5 of postnatal life. To evaluate the association between LV IRT, gestational age and FHR, bivariate regression analyses were performed. RESULTS: Mean LV IRT (62+/-8 ms) was 29 percent longer in FGR as compared to the normal subset (47+/-6 ms) at all gestational ages (p<0.001). Mean postnatal active plasma renin level (7.78+/-S.D. 1.03 ng/ml) and postnatal angiotensin I level (4.21+/-0.70 ng/ml) in the FGR subset were significantly higher (p<0.001) than in the normal subset (4.81+/-1.04 ng/ml, renin and 2.69+/-0.44 ng/ml, angiotensin I). There was a significant difference (p<0.01) in systolic blood pressure between the two subsets on postnatal day 1 (FGR 52+/-6 mmHg vs. normal 46+/-4 mmHg) and day 5 (FGR 76+/-5 mmHg vs. normal 60+/-6 mmHg). CONCLUSION: Left ventricular isovolumic relaxation time may act as a sensitive index of increased arterial afterload in the growth retarded fetus and may herald raised systolic blood pressure in the early neonatal period.
Authors: Anderson H Kuo; Cun Li; Jinqi Li; Hillary F Huber; Peter W Nathanielsz; Geoffrey D Clarke Journal: J Physiol Date: 2016-12-17 Impact factor: 5.182
Authors: Seema Mital; Wendy K Chung; Steven D Colan; Lynn A Sleeper; Cedric Manlhiot; Cammon B Arrington; James F Cnota; Eric M Graham; Michael E Mitchell; Elizabeth Goldmuntz; Jennifer S Li; Jami C Levine; Teresa M Lee; Renee Margossian; Daphne T Hsu Journal: Circulation Date: 2011-05-16 Impact factor: 29.690