Developmental changes in the left ventricular diastolic wall strain on M-mode echocardiography

The diastolic wall strain (DWS) of the left ventricle has been proposed as an indicator of left ventricular (LV) wall stiffness. The DWS is calculated as follows using M-mode echocardiography:[Formula: see text]Although this index is simple and clinically useful, normal values for children, including neonates, have not been reported.

The DWS was measured in 235 healthy people, ranging from neonates to adults. They were classified into 8 subgroups according to their age. The DWS was compared with conventional echocardiographic parameters for left ventricle function, including shortening fraction of the left ventricle, the Tei index, E/A of mitral flow, mitral annular tissue Doppler velocity during systole (s') and during early diastole (e'), and the E/e' ratio.

The DWS in the just after birth group was 0.28 ± 0.11, which was significantly lower than that of the remaining groups (p < 0.05), except for the neonate group at 5-10 days after birth. The DWS was highest in the 1-9 years of age group, and then gradually decreased with age. Stepwise regression of various echocardiographic parameters showed that e' was the most relevant parameter for the DWS (β = 0.64).

Normal values for the DWS of the left ventricle change with age. The data reported in this study can be used as normal values for the DWS of the left ventricle determined by M-mode echocardiography.