A comprehensive echocardiographic protocol for assessing neonatal right ventricular dimensions and function in the transitional period: Normative data and z scores

Abstract

Background There is a paucity of echocardiographic data describing right ventricular (RV) dimensions and function in the early transitional newborn period. Methods Fifty healthy term newborns underwent serial echocardiography at a mean of 15 ± 2 and 35 ± 2 hours of age. RV dimensions and functional indices were measured as recommended in the American Society of Echocardiography's recent guidelines. Additional novel parameters included RV anteroinferior basal diameter, fractional area change (FAC) from the apical three-chamber view, and speckle-tracking echocardiography-derived peak longitudinal strain in the RV lateral (apical four-chamber view) and inferior (apical three-chamber view) walls. Results obtained at both time points were compared. Results Linear dimensions and tissue Doppler velocities were highly reproducible, while time intervals and FAC measurements were more variable. Three-chamber FAC was higher than four-chamber FAC (36 ± 5% vs. 24 ± 7%, P.05). A small increase in RV dimensions was noted on day 2 of life (midcavity diameter, 1.71 ± 0.19 vs 1.55 ± 0.19 cm, P