Chronic lung disease (CLD), defined as oxygen requirement at 36 weeks corrected gestational age (CGA) is a significant neonatal morbidity which can have adverse effects on cardiac function until at least pre-school age.1 Conventional echocardiographic techniques are often insufficient to identify cardiac dysfunction in preterm infants. We have previously demonstrated that tissue Doppler imaging (TDI) may be a useful method of assessment of myocardial function in these patients.2Objectives
To compare myocardial function in preterm infants born at <32 weeks gestation with and without CLD using TDI.Methods
40 preterm infants with CLD (20 receiving low flow nasal cannula oxygen and 20 receiving non-invasive positive airway pressure) and 20 without CLD had an echocardiogram at approximately 36 weeks CGA. Myocardial function was evaluated using both conventional echocardiography and TDI. Institutional ethical approval and written parental consent were obtained.Results
The median GA and birth weight (BW) of infants with CLD was lower than controls (27wk (23–31) vs. 28 wk (23–31); 824 g (500–1640) vs.1030 g (570–1700)). There was no significant difference in persistence of PDA, tricuspid regurgitation, left ventricular fractional shortening and left ventricular output between the groups. However, right ventricular late diastolic velocities (A’) (p = 0.01); biventricular myocardial performance index (p ≤ 0.002); biventricular ejection times (p < 0.05) and biventricular isovolumetric contraction and relaxation times (p ≤ 0.003) were all significantly higher in CLD cases compared with controls. All measurements were similar between CLD cases requiring different levels of respiratory support.Conclusion
Using TDI in this vulnerable group of patients may improve the identification of cardiac dysfunction and guide further management.