Normative ranges of biventricular volumes and function in healthy term newborns

Cardiovascular magnetic resonance (CMR) is increasingly used in newborns with congenital heart disease. However, reporting on ventricular volumes and mass is hindered by an absence of normative data in this population.

Healthy term (37-41 weeks gestation) newborns underwent non-sedated, free-breathing CMR within the first week of life using the 'feed and wrap' technique. End-diastolic volume (EDV), end-systolic volume (ESV) stroke volume (SV) and ejection fraction (EF) were calculated for both left ventricle (LV) and right ventricle (RV). Papillary muscles were separately contoured and included in the myocardial volume. Myocardial mass was calculated by multiplying myocardial volume by 1.05 g/ml. All data were indexed to weight and body surface area (BSA). Inter-observer variability (IOV) was performed on data from 10 randomly chosen infants.

Twenty healthy newborns (65% male) with a mean (SD) birth weight of 3.54 (0.46) kg and BSA of 0.23 (0.02) m2 were included. Normative LV parameters were indexed EDV 39.0 (4.1) ml/m², ESV 14.5 (2.5) ml/m² and ejection fraction (EF) 63.2 (3.4)%. Normative RV indexed EDV, ESV and EF were 47.4 (4.5) ml/m², 22.6 (2.9) ml/m² and 52.5 (3.3)% respectively. Mean LV and RV indexed mass were 26.4 (2.8) g/m² and 12.5 (2.0) g/m², respectively. There was no difference in ventricular volumes by gender. IOV was excellent with an intra-class coefficient > 0.95 except for RV mass (0.94).

This study provides normative data on LV and RV parameters in healthy newborns, providing a novel resource for comparison with newborns with structural and functional heart disease.