Normative Data for Left and Right Ventricular Systolic Strain in Healthy Caucasian Italian Children by Two-Dimensional Speckle-Tracking Echocardiography

Background: There is an increasing interest in echocardiographic strain (epsilon) measurements for the assessment of ventricular myocardial function in children; however, pediatric nomograms remain limited. Our aim was to establish pediatric nomograms for the left ventricular (LV) and the right ventricular (RV) epsilon measured by two-dimensional speckle-tracking echocardiography (2D-STE) in a large cohort of healthy children prospectively enrolled. Methods: Echocardiographic measurements included STE LV longitudinal and circumferential and RV longitudinal global end-systolic epsilon. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Echocardiograms were performed by Philips-iE33 systems (Philips, Bothell, WA) and offline measurements on Philips-Q-Lab-9. Results: In all, 721 subjects (age 31 days to 17 years; 48% female) were studied. Low coefficients of determination (R-2) were noted among all of the epsilon parameters evaluated and adjusted for age, weight, height, BSA, and HR (i.e., R-2 all <= 0.10; range, 0.01-0.088). This hampered the possibility of performing z-scores with a sufficient reliability. Thus, we are limited to presenting data as mean values (+/- SD) stratified for age groups and divided by gender. LV longitudinal e values decreased with age (P < .001), while no significant age-related variations were noted for RV longitudinal epsilon. A significant base-to-apex (lowest to highest) gradient in circumferential LV epsilon values was noted at all ages (P < .001). Conclusions: We report pediatric echocardiographic normative data for 2D-STE for the LV and RV epsilon by using vendor-specific software. Our results confirm previous observations, showing only little variations of strain parameters with age and gender.