Abstract 13613: 4D Echo-Derived Global Area Strain is a Better Mechanical Index of RV Function

Abstract

Introduction: There is increasing interest in image based evaluation of RV mechanics. Hypothesis: Four-dimensional echocardiography (4DE) accurately assesses RV function, compared against sonomicrometry. Methods: Six porcine RV models were studied. Each RV was connected to a pump apparatus to generate pulsatile motion. Six sonomicrometry (sono) crystals were sutured in a triangle formation onto the RV to acquire volume. Right ventricular ejection fraction (RVEF), 3D global area strain (GAS), global circumferential strain (GCS), global longitudinal strain (GLS), and global radial strain (GRS) were obtained by 4D echocardiography at stroke volumes of 30-70 ml. Results were correlated with RVEF determined by sonomicrometry analysis. Results: Linear regression of all EchoPAC-derived parameters, RVEF, GAS, GCS, GLS, and GRS showed strong correlations with RVEF from sono data (r = 0.73, r = 0.78, r = 0.72, r = 0.75, r = 0.75, respectively; all P < 0.001). Bland-Altman analyses showed a slight over-estimation of echo-derived 3D RVEF and strain when compared to sono-derived EF, but more than 95% of data points were within the limits of agreement. Conclusions: 4DE demonstrates the ability to accurately and feasibly assess RV function, and GAS showed the highest correlation with the reference ejection fraction.