Right ventricular Tei index in children: effect of method, age, body surface area, and heart rate.

The right ventricular (RV) Tei index (RVTX) has been used to analyze systolic and diastolic global RV function in various congenital and acquired cardiac abnormalities in children. We conducted a study to determine the effects of the methods of Doppler tissue imaging (DTI) versus pulse wave Doppler (PWD) and age, body surface area (BSA), and heart rate on the RVTX in a population of 308 children with normal echocardiogram findings. Participants ranged in age from 1 day to 18 years, with BSA from 0.08 to 2.4 m2 and heart rate from 46 to 182/min. The RVTX was calculated by both DTI and PWD in each patient during a single echocardiographic examination. RVTX-DTI = 0.37 +/- 0.05 (mean +/- SD) versus RVTX-PWD = 0.34 +/- 0.06 were slightly but statistically different (P < .001). Univariate linear regression analysis showed age and BSA both had small but significant positive effects on both the RVTX-DTI and RVTX-PWD, and heart rate had a small but significant negative effect on both techniques (all with P < .01). By multivariate regression analysis RVTX-DTI was significantly affected only by the BSA and the RVTX-PWD only by age (both with P < .05). Therefore, one must consider the method of RVTX measurement, the BSA for RVTX-DTI, and the age for RVTX-PWD to accurately assess RVTX values.