Longitudinal follow-up of ventricular performance in healthy neonates

Abstract

BackgroundSpecific follow-up of newly introduced echocardiographic parameters in healthy neonates and infants is limited. AimTo prospectively describe follow-up of left ventricular (LV) tissue Doppler imaging (TDI) and speckle tracking strain parameters in healthy subjects up to two months after birth. DesignThis is a longitudinal follow-up study. SubjectsTwenty-eight (10 male) healthy newborns were included and underwent transthoracic echocardiography 1–3days, 3weeks and 6–7weeks after birth. Outcome measuresIn each echocardiogram, parameters describing cardiac growth, including LV mass (LVM), were assessed. Additionally, TDI derived peak systolic velocity (S′) and peak early (E′) and late (A′) diastolic velocities were assessed in the basal LV free wall and interventricular septum (IVS). Finally LV longitudinal, radial and circumferential global peak strain parameters were assessed using speckle tracking strain imaging. ResultsLVM significantly increased during follow-up (7.6±2.4 versus 12.4±3.2g, p=0.002). Similarly at 1–3days versus 6–7weeks after birth, an increase in LV and IVS systolic (LV S′ 4.1±1.5 versus 6.3±1.5cm/s, p=0.001; IVS S′ 3.6±0.9 versus 6.4±1.3cm/s, p<0.001) and diastolic (LV E′ 6.1±2.2 versus 9.7±2.9cm/s, p=0.002; IVS E′ 5.1±1.4 versus 10.7±3.3cm/s, p<0.001) TDI parameters was observed. In contrast, global peak longitudinal, radial and circumferential strain parameters did not significantly change during follow-up. ConclusionsA significant increase in LV systolic and diastolic TDI parameters was observed up to two months after birth. Yet this increase may be (cardiac) growth-dependent. No significant changes were observed in speckle tracking strain derived global peak strain parameters; this may render the technique particularly valuable in evaluation of LV systolic performance during periods of significant growth, such as the neonatal period.