Bakground Low Vitamin D levels have been linked to cardiac failure in the adults and children. Tissue Doppler Imaging (TDI) is evolving as a superior measure of subtle changes in myocardial contractility in preterm infants. We aimed to correlate Vitamin D levels at birth with TDI measures of systolic and diastolic function.
Methods Preterm infants < 32 weeks gestation were recruited. Vitamin D levels were measured at birth and echocardiography was carried out on Day 1. TDI myocardial velocities were recorded using a pulsed wave doppler sample from the lateral left/right ventricular wall & intraventricular septum. Peak systolic (S’), early diastolic (E’) and late diastolic (A’) velocities were recorded.
Results Ten preterm infants with structurally normal hearts were recruited. Mean (SD) gestational age was 28 (1.7) weeks and birthweight 1.29 (0.3)kg. There was no significant increase in Right ventricular systolic (5.1cm/sec vs 4.8cm/sec)or diastolic myocardial velocity measures (5.2cm/sec vs 5.1cm/sec) or left myocardial velocity systolic (3.7cm/sec vs 3.9cm/sec) or diastolic (4.1cm/sec vs 4.0cm/sec) measures between those with severe Vitamin D deficiency (<30 nmol/L) and those with low normal levels of Vitamin D.
Conclusion Neonates with severe Vitamin D deficiency have similar TDI measures of systolic and diastolic velocity to those with near normal levels. In our small cohort severe Vitamin D deficiency appears to cause no impairment in myocardial contractility.