Development of left and right ventricular function in healthy children explored by tissue Doppler imaging

Abstract

Objective To explore the development and interaction of left and right ventricular function in healthy children using tissue Doppler imaging. Methods Healthy children aged 0-15 years and adolescents were recruited, then children were divided into 6 groups: 0-1 year, >1-3 years, >3-6 years, >6-9 years, >9-12 years, >12-15 years.Healthy adolescents aged >15-25 years were also recruited.Every subject underwent echocardiography including cardiac dimension measurements, atrio-ventricular valvular velocity and early-diastolic flow velocity€/late-diastolic flow elocity(A) ratio measured by pulsed color Doppler, atrio-ventricular annular myocardial velocity (including systolic velocity 's', early diastolic velocity 'e' and late diastolic velocity 'a'), time intervals (including isovolumic contraction time, ejection time and isovolumic relaxation time), isovolumic acceleration (IVA) and Tei index measured by tissue Doppler imaging.Results were compared among different groups, the correlations with age and other factors were explored.Furthermore, comparison was done between left and right ventricular functional parameters. Results Left ventricular Tei index and isovolumic contraction time were significantly lower during puberty.From infancy to pre-school stage, left ventricular E/A(flow velocity) and e/a(tissue velocity) increased accordingly, then presented with no significant changes among the following age groups(P>0.05). There were no significant differences in right ventricular Tei index, IVA, E/A(flow velocity) and e/a(tissue velocity) among the 6 groups(P>0.05). Left ventricular systolic myocardial velocity(s) and IVA were significantly lower than right ventricle (all P<0.001). However, left ventricular E/e(flow velocity) and e/a(tissue velocity) were significantly greater than right ventricle (all P<0.001). Conclusions In healthy children, left ventricular systolic function enhances during puberty, diastolic function increases from infancy to pre-school stage, then keeps stable till adolescents.Right ventricular systolic and diastolic function present with no significant changes during growth.Left ventricular diastolic function is greater than right one, however, right ventricular longitudinal systolic function is greater than left one. Key words: Healthy child; Left ventricular function; Right ventricular function; Tissue Doppler imaging