Right ventricular longitudinal strain is diminished in systemic sclerosis compared with idiopathic pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterised by severe progressive remodelling of pulmonary arterioles resulting in chronic right ventricular (RV) overload 1. Regardless of aetiology, RV adaptation to increased pressure load is the main determinant of outcome in PAH 2–4; however, mortality because of RV failure is significantly higher in systemic sclerosis-related PAH (SSc-PAH) than in idiopathic PAH (IPAH) 5. Using invasive pressure–volume assessments, we have previously shown that SSc-PAH patients have depressed RV contractility compared with IPAH at similar afterloads 6. However, the invasive nature of pressure–volume haemodynamics along with the significant expense and technical expertise makes this technique less feasible for routine clinical practice. Although two-dimensional echocardiogram (2DE) is a useful screening tool in PH, RV dysfunction may be often undetected or underestimated, partly because of the complex geometric configuration of the RV chamber and misalignment of the Doppler beam for noninvasive haemodynamic assessment. Speckle-tracking echocardiography (STE), an echo-based imaging modality used in conjunction with 2DE, allows offline calculation of myocardial velocities and deformation parameters in the assessment of regional myocardial contractility 7. Our group recently demonstrated a heterogeneous pattern of RV longitudinal systolic strain (RVLSS) utilising STE in SSc patients with variable afterloads, which was not appreciable by 2DE alone 8. Our findings, however, were shown in a cross-sectional analysis of asymptomatic SSc patients without symptomatic RV failure, right heart catheterisation (RHC)-confirmed PAH or with echocardiographic evidence of RV dilatation. In the current study, we applied this STE-based technique to PAH patients with baseline RV dysfunction to determine whether there were global and regional differences in RVLSS that might distinguish SSc-PAH from IPAH at similar afterload. Our findings have been previously presented in abstract form 9. Speckle tracking echo is a useful clinical tool to distinguish differential RV contractility between PAH subtypes