Reference ranges of left ventricular diastolic multimodal ultrasound parameters in stable preterm infants in the early and late neonatal intensive care admission period

BACKGROUND: Diastolic dysfunction often precedes systolic dysfunction and provides opportunity for management strategies. We aim to present reference ranges for diastolic function parameters in stable preterm infants at 2 timepoints. METHODS: Ultrasound scans of clinically stable preterm infants < 30 weeks gestation with no antenatal or postnatal complications were analysed for left heart size, mitral blood flows, myocardial velocities and shortening during the early (3 to 21 days) and late (corrected gestation 34 to 37 weeks) neonatal period. RESULTS: 92 early scans and 64 late scans were included. Mitral blood flow and myocardial velocities increased with augmented atrial function leading to higher EA and e'a' ratios and with relatively high Ee' ratio. CONCLUSION: We present reference values for many left ventricular multimodal diastolic ultrasound parameters in preterm infants with uncomplicated fetal and neonatal development to guide prospective studies that explore diastolic function and diastolic heart failure in preterm infants.