Objectives: The feasible application of vector flow mapping (VFM)-derived right ventricular (RV) energy loss (EL) is lacking. This study was designed to determine reference values of VFM-derived EL within the right ventricle and evaluate potential correlated variables.
Methods: A total of 90 healthy children were enrolled. Velocity vector fields of the intra-RV outflow tract and pulmonary trunk (OP) and RV blood flow were obtained from the parasternal short-axis view and RV focused apical 4-chamber view, respectively. RV-EL and OP-EL values during diastole and systole were calculated using VFM analysis. The potential relationships between demographic and echocardiographic parameters and the dissipative EL were also identified.
Results: Mean subject age was 8.99 ± 5.35 years. The median (interquartile range) values were 8.82 (5.47-14.30) W/m for RV diastolic EL, 3.17 (2.11-5.54) W/m for RV systolic EL, 18.82 (13.93-24.92) W/m for OP diastolic EL, and 29.88 (20.62-40.78) W/m for OP systolic EL, respectively. The dissipative EL values were negatively correlated with age and RV global strain, and positively correlated with heart rate and RV Tei index. Multivariate analysis showed that age was the primary independent predictor of these 4 types of EL, while heart rate and strain were contributors of the RV diastolic EL and OP systolic EL.
Conclusions: The present study initially validated the application of vector flow mapping-derived EL analysis in right ventricle and established reference values for the future assessment of children with cardiopulmonary disease. Age, heart rate, and strain were independent variables correlated with the dissipative EL.
Keywords: cardiac function; children; echocardiography; right ventricular energy loss; vector flow mapping.
© 2018 by the American Institute of Ultrasound in Medicine.