Characterization of Right Ventricular Deformation in Pulmonary Arterial Hypertension Using Three-Dimensional...

Pulmonary arterial hypertension (PAH) can cause maladaptive right ventricular (RV) functional changes associated with adverse prognosis that are challenging to accurately quantify noninvasively. The aim of this study was to explore principal strain (PS) with contraction angle analysis using three-dimensional echocardiography to characterize RV deformation changes in patients with PAH.

Three-dimensional echocardiography was performed in 37 patients with PAH and 20 healthy control subjects with two-component (primary and secondary) PS and principal contraction angle analysis. Patients were stratified according to World Health Organization (WHO) functional class.

Primary PS differed significantly between patients with PAH and healthy control subjects (-20.2 ± 3.3% vs -26.8 ± 3.3%, P = .01), while secondary PS was not significantly different (3.6 ± 5.1% vs -2.5 ± 4.7%, P = .12). Principal contraction angle was significantly lower in patients with PAH (63 ± 22° vs 71 ± 7°, P = .01), with the greatest reduction for the RV free wall. Primary PS and principal contraction angle differed significantly between WHO class I and II and class III and IV patients (-23.9 ± 4.7% vs -18.1 ± 4.8% [P = .03] and 69 ± 9° vs 58 ± 14° [P = .03], respectively), while secondary PS was not significantly different between groups (P = .13). Compared with healthy control subjects, septal principal contraction angle was not different in patients with WHO class I and II PAH (P = .62), but it was significantly reduced in those with WHO class III and IV PAH (P < .01). The area under the curve for primary PS to differentiate patients with PAH by WHO functional class was 0.81 (95% CI, 0.77-0.89; P = .01). Primary PS intraclass correlation coefficients for intraobserver and interobserver variability were 0.91 (95% CI, 0.88-0.93) and 0.86 (95% CI, 0.81-0.88), respectively.

PS analysis using three-dimensional echocardiography provides comprehensive quantification of RV deformation and characterizes alterations occurring in PAH that are associated with WHO functional class.