Introduction Haemodynamic changes occurring during the fetal – neonatal transition may impact on global myocardial function in the first week of life. Tissue Doppler imaging (TDI) offers a novel technique to measure changes in systolic and diastolic function in neonates.
Aims To use TDI to assess myocardial function in preterm infants compared to gold standard measures.
Methods Preterm infants < 32 weeks gestation were recruited. Echocardiography was carried out by a single observer (KA) using the GE Vivid I, on Day 1, 3–4 and Day 7. Clinical parameters were recorded at time of echocardiogram. Standard M mode echocardiography was used to determine shortening and ejection fraction. Myocardial velocities were obtained using a pulsed wave doppler sample from the lateral mitral/tricuspid annuli and intraventricular septum from an apical four chamber view. Peak systolic (S’), early diastolic (E’) and late diastolic (A’) velocities were recorded.
Results 140 echocardiograms were performed on 60 neonates with structurally normal hearts. Gestational age range-23+ 6–31+ 6 weeks. There was a significant increase in heart rate (p=0.002)and systolic blood pressure over the 1st week. (p=0.001). There was an increase in myocardial velocities across all measurements, with right ventricular early systolic and late diastolic velocities increasing significantly (p<0.002). There was a significant increase in the left ventricle late diastolic velocities (p=0.036). There was no significant difference in shortening/ejection fraction over the first week.
Conclusion TDI offers a reliable measure of myocardial velocities over the first week. Current gold standard measures shortening/ejection fraction showed no significant change in myocardial contractility however TDI demonstrated significant changes in both RV and LV systolic and diastolic velocities.