BACKGROUND: Increased systolic pulmonary artery pressure (sPAP) could lead to mechanical dysfunction and myocardial fibrosis of right heart chambers. Echocardiographic strain analysis has not been adequately studied in patients living with pulmonary hypertension (PH). METHODS AND RESULTS: A cross-sectional cohort of patients with suspected PH and echocardiographic strain evaluation was recruited. Cut-off values of peak tricuspid regurgitation velocity with low probability of PH (≤ 2.8 m/s), intermediate probability (2.9-3.4 m/s, without other echo PH signs) and high probability of PH (2.9-3.4 m/s with other echo PH signs and >3.4 m/s) categories were studied by right ventricular and right atrial strain analysis in a sample of 236 patients, 58 (56.9%) had low, 15 (14.7%) intermediate, and 29 (28.4%) high probability of PH. We observed a negative association between right ventricular free wall strain and atrial global strain with sPAP. As PH severity increased, right atrial reservoir, conduit, and contraction (booster) strain values decreased. Identified cut-off values of strain parameters had an adequate ability to detect PH severity categories In addition, post-mortem biopsies of right heart chambers from subjects with known severe pulmonary hypertension were analyzed to quantify myocardial fibrosis. Our sample of right heart biopsies (n=12) demonstrated an association between increased sPAP before death and right ventricular and right atrial fibrosis. CONCLUSIONS: Mechanical dysfunction and fibrosis in right chambers is associated with increased sPAP. Right ventricular and atrial strain could provide enhancement in the diagnosis and categorization of subjects with suspected PH.

Purpose: This study was a quality-control study of resting and exercise echocardiography (EDE) variables measured by 19 echocardiography laboratories with proven experience participating in the RIGHT Heart International NETwork. Methods: All participating investigators reported the requested variables from ten randomly selected exercise stress tests. Intraclass correlation coefficients (ICC) were calculated to evaluate the inter-observer agreement with the core laboratory. Inter-observer variability of resting and peak exercise tricuspid regurgitation velocity (TRV), right ventricular outflow tract acceleration time (RVOT Act), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid lateral annular systolic velocity (S’), right ventricular fractional area change (RV FAC), left ventricular outflow tract velocity time integral (LVOT VTI), mitral inflow pulsed wave Doppler velocity (E), diastolic mitral annular velocity by TDI (e’) and left ventricular ejection fraction (LVEF) was measured. Results: The accuracy of 19 investigators for all variables ranged from 99.7% to 100%. ICC was > 0.80 for all observers. Inter-observer variability for resting and exercise variables was for TRV = 3.8 to 2.4%, E = 5.7 to 8.3%, e’ = 6 to 6.5%, RVOT Act = 9.7 to 12, LVOT VTI = 7.4 to 9.6%, S’= 2.9 to 2.9% and TAPSE = 5.3 to 8%. Moderate inter-observer variability was found for resting and peak exercise RV FAC (15 to 16%). LVEF revealed lower resting and peak exercise variability of 7.6 and 9%. Conclusions: When performed in expert centers EDE is a reproducible tool for the assessment of the right heart and the pulmonary circulation