Longitudinal strain curves in the RV free wall differ in morphology in patients with pulmonary hypertension compared to controls

Background: Previous studies using speckle tracking-derived strain for quantification of right ventricular (RV) function in pulmonary hypertension (PHT) have focused on the magnitude of global and regional peak longitudinal systolic strains (PLSS) and systolic strain-related indices of dyssynchrony. The aim of our study was to investigate the pattern of RV contraction and relaxation with the use of the contour and timing of strain and velocity curves in PHT.

Methods: The study population consisted of thirty-seven patients with PHT (45 ± 18 years, 16 women) and thirty-seven controls. A complete two-dimensional echo with speckle-tracking-derived longitudinal strain of the basal RV free wall and interventricular septum (IVS) was performed and the cycle length-corrected time to PLSS (SST) and time from PLSS to 50% of PLSS (systolic strain half time-SSHT) in both regions were calculated.

Results: Patients with PHT had significantly reduced PLSS (-24.9 ± 2.0% vs -43.2 ± 3.0%, p<0.001) and increased SST (0.47 ± 0.02 vs 0.39 ± 0.02, p=0.043) and SSHT (0.22 ± 0.02 vs 0.16 ± 0.02, p=0.047) in the basal RV free wall compared to controls. Furthermore, peak systolic velocities were observed earlier in the cardiac cycle in both regions in patients with PHT compared to controls.

Conclusions: Longitudinal strain curves in the RV free wall reach peak values later in the cardiac cycle and return slower towards the baseline in PHT. Furthermore, peak systolic velocities are observed earlier in the cardiac cycle in both the basal RV free wall and the basal IVS. The above observations effectively illustrate changes in patterns of RV contraction and relaxation caused by PHT.