Abstract 19604: Global Longitudinal Strain in Different Right Ventricular Walls Using Alternate Right Ventricular Apical Views: Validation and Establishment of Normal Values in Children

Abstract

Introduction: Right ventricular (RV) function is an important prognostic factor in congenital and acquired heart disease. Quantitative measures of RV lateral wall function obtained from the apical 4 chamber (A4C) view are used to extrapolate global RV function. We aimed to use non-standard views of the RV to establish normal global longitudinal strain (GLS) in additional walls of the RV in healthy children to allow a more comprehensive RV assessment. Methods: A total of 88 healthy children (age 5-17 years) were recruited in a prospective, multi-institutional study. Images were acquired with the Vivid E-9 with post-processing performed using EchoPac (GE Ultrasound). RV views similar to LV apical 2 chamber (A2C) and apical 3 chamber (A3C) views were performed with care taken to exclude septal myocardium. GLS in the RV lateral (A4C), inferior (A2C) and posterior (A3C) walls were averaged over 3 cardiac cycles and calculated if at least 2 of 3 wall segments tracked. A global RV strain assessment was calculated by averaging the 3 available walls. Intraobserver variability was assessed. Results: GLS was measurable in 67% of lateral, 75% of inferior and 45% of posterior walls analyzed. The normal ranges for GLS across the pediatric age group are shown in figure 1. Overall, we observed a decrease in lateral wall GLS with increasing age; inferior and posterior GLS changed less with age. Average global RV strain was -31.3% +/- 2.4%. Intraobserver reliability in 15 patients showed coefficient of variance of 5.2%, 3.9% and 4% with no significant bias in the lateral, inferior and posterior walls. Conclusions: This report establishes reference values for inferior and posterior RV wall strain in children. We show that speckle tracking strain analysis is feasible in alternate walls of the RV allowing for more global assessment of RV function. Establishment of normal values in a larger cohort including younger children may improve future assessment of dysfunction in RV pathology.