Tissue Doppler imaging of left and right ventricles in normal children

Tissue Doppler imaging is a new ultrasound technology that derives measurem ents of contraction and relaxation velocities directly from the myocardium. However, data on myocardial velocities by using tissue Doppler imaging hav e not been established in normal children. In 48 normal children, myocardia l velocities were measured using tissue Doppler imaging at three different sites (base, middle, and apex) in the left and right ventricles and the int erventricular septum. In the left ventricular wall, the peak myocardial vel ocities during early diastole (peak E), during atrial contraction (peak A), and during systole (peak S) waves decreased gradually between the base and apical sites, whereas the ratio of E to A waves (peak E/A wave ratio) did not change among the 3 segments. Similar findings were obtained from the my ocardial velocities in the right ventricle and the interventricular septum. A systolic and diastolic velocity gradient was also observed between the d ifferent ventricular walls. Significant correlations of the tissue Doppler parameters with age or heart rate were observed. In the left ventricle, the peak E wave demonstrated a stronger relation with age (r = 0.77) than with heart rate (r = -0.65). The peak A. wave did not change with age but corre lated with heart rate. The peak E/A wave ratio showed a weaker relation wit h age (r = 0.54) than with heart rate (r = 0.62). The peak S wave was relat ed to age (r = 0.6) and to a lesser extent to heart rate (r = -0.51). Simil ar relationships of tissue Doppler parameters with age or heart rate were o bserved for the right ventricle and interventricular septum. The heterogene ous pattern and age- and heart-rate-related changes in normal myocardium de monstrated in this study must be taken into account when attempting to iden tify altered regional myocardial function with tissue Doppler echocardiogra phy. (C) 2000 Tohoku University Medical Press.