Abstract 10317: Maturational Changes in Myocardial Mechanics During the First Month of Life in Healthy Full term Neonates
Background: Cardiac mechanics undergo maturational changes in the postnatal period, which influence long term cardiac function. 2D speckle tracking echocardiography (2DSTE) derived myocardial strain, a measure of cardiac deformation, can be used to quantitatively assess the changes in myocardial mechanics. The objective of this study was to determine longitudinal maturational changes in the left and right ventricular mechanics with 2DSTE derived strain during the first month of life in healthy full term neonates.
Methods: Peak global longitudinal strain (GS), systolic strain rate (GSRs), and segmental longitudinal strain (SS) at the apical, mid, and basal ventricular levels in the RV free wall (RVFW), septum, and LV free wall (LVFW) were measured in 40 healthy full term infants. Measurements were obtained @ birth (4 ± 2 days, n=13) and 1 mo. of life (30 ± 7 days, n=27) using standard and 2DSTE (GE EchoPac), and were compared.
Results: LV GS and GSRs remained unchanged from birth until one month (p=0.14), whereas RV and septal GS and GSRs significantly increased (p=0.02). By 1 month, GS, GSRs, and SS were significantly larger (p=0.03) in RVFW than in LVFW. There was a significant base-to-apex SS gradient (p<0.001) in the RVFW and a reverse apex-to-base gradient in the LVFW (p<0.001) that existed from birth to 1 month. A base-to-apex gradient existed for septal SS at birth that significantly (p=0.05) reversed by 1 month (Figure 1).
Conclusions: LV GS and GSRs remain unchanged with a stable apex to base gradient in the LVFW suggesting relative constant LV mechanics with maturation. RV SS had a stable base-to-apex gradient that highlights the dominant deep longitudinal layers of the RV that are aligned base to apex. RV GS and GSRs increase with maturation, and septal SS reverses its gradient from an RV to LV arrangement with maturation that may reflect normal postnatal loading conditions and consequential developing cardiac mechanics in healthy full term neonates (NIH 1U01 HL1014650).
- © 2013 by American Heart Association, Inc.