Three-Dimensional Speckle Tracking of the Right Ventricle: Toward Optimal Quantification of Right Ventricular Dysfunction in Pulmonary Hypertension

Abstract

BackgroundQuantitative assessment of right ventricular (RV) systolic function largely depends on right ventricular ejection fraction (RVEF). Three-dimensional speckle tracking (3D-ST) has been used extensively to quantify left ventricular function, but its value for RV assessment has not been established. ObjectivesThis study sought to prospectively assess whether 3D-ST would be a reliable method for assessing RV systolic function and whether strain values were associated with survival. MethodsComprehensive 2-dimensional echocardiographic assessment, 3D-ST of the RV free wall, and measurement of RVEF was performed in 97 consecutive patients with established pulmonary hypertension (PHT) (RVEF 31.4 ± 9.6%, right ventricular systolic pressure [RVSP] 76.5 ± 26.2 mm Hg) and 60 healthy volunteers (RVEF 43.8 ± 9.4%, RVSP 25.9 ± 4.3 mm Hg). ResultsArea strain (AS) (−24.3 ± 7.3 vs. −30.8 ± 7.2; p < 0.001), radial strain (23.2 ± 14.4 vs. 34.9 ± 18.2; p < 0.001), longitudinal strain (LS) (−15.5 ± 3.8 vs. −17.9 ± 4.4; p = 0.001), and circumferential strain (CS) (−12.2 ± 4.5 vs. −15.7 ± 6.1; p < 0.001) were all reduced in patients with PHT, compared with normal individuals. AS and CS strongly correlated to RVEF (r = 0.851, r = −0.711; p < 0.001). Systolic dyssynchrony index was greater in PHT (0.14 ± 0.06 vs. 0.11 ± 0.07; p = 0.003) and correlated to RVEF (r = −0.563, p < 0.001). AS (hazard ratio [HR]: 3.49; 95% confidence interval [CI]: 1.21 to 7.07; p = 0.017), CS (HR: 4.17; 95% CI: 1.93 to 12.97; p < 0.001), LS (HR: 7.63; 95% CI: 1.76 to 10.27; p = 0.001), and RVEF (HR: 2.43; 95 CI: 1.00 to 5.92; p = 0.050) were significant determinants of all-cause mortality. Only AS (p = 0.029) and age (p = 0.087) were predictive of death after logistic regression analysis. ConclusionsPHT patients have reduced RV strain patterns and more dyssynchronous ventricles compared with controls, which was relatable to clinical outcomes. AS best correlated with RVEF and provides prognostic information independent of other variables.