Utility of Right Ventricular Free Wall Speckle-Tracking Strain for Evaluation of Right Ventricular Performance in Patients with Pulmonary Hypertension

Abstract

The objectives of this study were to test the utility of right ventricular (RV) speckle-tracking strain as an assessment tool for RV function in patients with pulmonary hypertension (PH) compared with conventional echocardiographic parameters and to investigate the relationship of the findings obtained with RV speckle-tracking strain with the hemodynamic parameters of RV performance. Forty-five prospective consecutive patients with PH were studied. RV free wall longitudinal speckle-tracking strain (RV-free) and RV septal wall longitudinal speckle-tracking strain (RV-septal) were calculated by averaging each of three regional peak systolic strains along the entire right ventricle. The conventional echocardiographic parameters-RV fractional area change, RV myocardial performance index, tricuspid annular plane systolic excursion, and tricuspid annular peak systolic velocity-were also studied. For comparison, 22 age-matched volunteers with normal ejection fractions were studied. RV-free in patients with PH was significantly lower than that in normal controls, but RV-septal in the two groups was similar. Importantly, multivariate analysis revealed that RV-free was an independent echocardiographic predictor of hemodynamic RV performance items, including mean pulmonary artery pressure (β=-0.844, P= .001) and pulmonary vascular resistance (β= -0.045, P < .001). RV-free was also correlated with RV ejection fraction and RV end-systolic volume measured by cardiac magnetic resonance imaging and with 6-min walking distance (r= 0.60, r= 0.56, and r= 0.49, respectively, P < .05). Furthermore, the improvement in RV-free 5 ± 3 months after adding medical treatment was significantly correlated with that in 6-min walking distance (r= 0.68, P < .0001). RV-free has the potential to allow for noninvasive follow-up of patients with PH.