The normal right ventricle in young people: assessment of volumes and myocardial deformation properties by three-dimensional echocardiography and Speckle tracking

Abstract

Background: Right ventricular (RV) function plays an important role in determining cardiac symptoms in several diseases. It has been demonstrated that the new imaging modality of three-dimensional echocardiography (3DE) is interchangeable to cardiac magnetic resonance in reproducibility and accuracy. Speckle Tracking is a sensitive tool to quantitatively assess regional deformation properties. Purpose: To obtain normal reference ranges for RV volumes, RV EF, by 3DE (TomTec) and RV deformation properties by Speckle Tracking and intra and inter-observer reproducibility. Methods: 60 subjects, 32 males and 28 females, aged 25±7 yrs, without any cardiovascular disease, were included. By E9GE we measured RV maximum and minimum volumes by tracing RV endocardial borders during enddiastolic (largest RV volume) and end-systolic (smallest RV volume) phases, in apical 4-chamber, short-axis, and coronal views. Volumes were indexed for body surface. By Speckle tracking we measured 2D longitudinal systolic RV Strain (S) and Strain rate (SR) in apical 4-chambers view, at level of RV free wall (basal, medium and apical segments). A reproducibility study was performed to compare the intra and inter-observer variability. Results: We have reported references range in young people for volumes and EF (3D RV end-diastolic:33±11ml/mq; end-systolic volume:16±6ml/mq; 3D RVEF 67±8%). RV systolic 2D S values in young people were for apical segment -24,59±4,8%, for medium -29,69±4,78%, for basal -30,1±5,88% and RV systolic 2D SR were for apical -1,44±0,25 S-1, for medium: -1,78±0,37 S-1, for basal:-2±0,4 S-1. Inter and intraobserver variability coefficients were 8% and 7% for 3D volumes and 8% and 4% for S-SR measurements, respectively. Conclusions: The present study provides normal reference values for RV volumes and RVEF by 3DE and normal longitudinal RV deformation values in young people. 3DE is an alternative imaging modality for quantification of RV volumes and EF, showing improved accuracy and lower interobserver and intraobserver variability compared to 2D echocardiography; it overcomes the limitations due to the complex anatomy of the RV.