Left and right ventricular strain and strain rate measurement in normal adults using velocity vector imaging: an assessment of reference values and intersystem agreement

Abstract

Velocity vector imaging (VVI) software permits quantitative assessment of ventricular function through measurement of myocardial strain (S) and strain rate (SR). The purpose of this study was to define a reference range of ventricular S and SR values in normal adults using VVI software, and to describe the variability among observers and systems. Two-dimensional echocardiography was performed in 186 healthy adults free of cardiovascular disease or risk factors, followed by comprehensive ventricular S and SR analysis using VVI software. Images were acquired using three commercial ultrasound systems. The mean age of patients was 44 ± 16 years, and 114 (61 %) were female. Mean global left ventricular (LV) longitudinal, circumferential, and radial S and SR, and right ventricular (RV) longitudinal S and SR values are presented. Significant segmental variation in regional LV and RV S and SR was detected. Multivariate regression analysis demonstrated global longitudinal LV (p = 0.05) and RV (p = 0.002) S values decline significantly with age. The overall variability of S and SR values accounted for by patient demographic and hemodynamic variables was low (16 and 8 % for LV longitudinal S and SR, respectively). Interobserver agreement was very good, but was lowest for LV radial S and SR. There were no significant differences of LV and RV S and SR between ultrasound systems. Comprehensive reference values for the normal ranges of LV and RV S and SR measured using VVI software are presented. The ultrasound system used for image acquisition did not significantly influence results.