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Tissue doppler imaging of left and right ventricles in normal children
K Hiarada1, T Orino, K Yasuoka
1Department of Pediatrics, Akita University School of Medicine, Japan. k-harada@doc.med.akita-u.ac.jp
Insights
Tissue Doppler imaging reveals normal myocardial velocity gradients in children. These velocities vary with age and heart rate, crucial for interpreting pediatric cardiac function.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Imaging
- Echocardiography
Background:
- Tissue Doppler imaging (TDI) is an ultrasound technique measuring myocardial velocities.
- Established reference data for TDI-derived myocardial velocities in healthy children are lacking.
Purpose of the Study:
- To establish normal myocardial velocity values using TDI in children.
- To investigate age and heart rate influences on these velocities.
Main Methods:
- TDI assessed myocardial velocities (peak E, peak A, peak S, peak E/A ratio) in 48 healthy children.
- Measurements were taken at base, middle, and apex of left ventricle, right ventricle, and interventricular septum.
Main Results:
- Myocardial velocities (peak E, peak A, peak S) decreased from base to apex.
- Peak E/A ratio remained consistent across segments.
- Significant correlations were found between TDI parameters, age, and heart rate.
Conclusions:
- Normal pediatric myocardium exhibits velocity gradients and age/heart rate dependencies.
- These findings are essential for accurate interpretation of regional myocardial function using TDI in children.
Abstract:
Tissue Doppler imaging is a new ultrasound technology that derives measurements of contraction and relaxation velocities directly from the myocardium. However, data on myocardial velocities by using tissue Doppler imaging have not been established in normal children. In 48 normal children, myocardial velocities were measured using tissue Doppler imaging at three different sites (base, middle, and apex) in the left and right ventricles and the interventricular septum. In the left ventricular wall, the peak myocardial velocities 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 myocardial velocities in the right ventricle and the interventricular septum. A systolic and diastolic velocity gradient was also observed between the different 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 correlated with heart rate. The peak E/A wave ratio showed a weaker relation with age (r=0.54) than with heart rate (r=0.62). The peak S wave was related to age (r=0.65) and to a lesser extent to heart rate (r= -0.51). Similar relationships of tissue Doppler parameters with age or heart rate were observed for the right ventricle and interventricular septum. The heterogeneous pattern and age- and heart-rate-related changes in normal myocardium demonstrated in this study must be taken into account when attempting to identify altered regional myocardial function with tissue Doppler echocardiography.