To assess the right atrial(RA) function using two-dimensional speckle-tracking echocardiography(2D-STE) and the value of predicting WHO functional class in patients with pulmonary hypertension(PH).

Fifty-four consecutive PH patients were studied and compared with a control group of 24 healthy volunteers.RA function was evaluated by 2D-STE, and the following parameters were recorded: an average longitudinal strain (LS) curve that included LSpos during RA filling and LSneg representing RA active contraction (their summation is LStot), the phasic RA volumes, total RA emptying fraction (TotEF), RA passive(PassEF) and active emptying fraction(ActEF). The associations between these indices and the results of invasive pulmonary hemodynamics, cardiac structure and function level were evaluated.

LStot, TotEF, LSpos, PassEF were significantly lower in PH patients than in controls(all P<0.01). ActEF/TotEF were significantly higher in WHO functional class (WHO-FC) Ⅱ and WHO-FC Ⅲ patients than in controls(all P<0.05), while were lower in WHO-FCIV patients than in controls(P<0.001). Among PH patients, LStot was negatively correlated with greater RA size and RA pressure (all P<0.01). LStot was also associated with right ventricular (RV) functional and overload parameters.In receiver-operator characteristic analysis, RA LStot was of optimal accuracy for prediction of WHO-FC≥Ⅲ in PH patients (P=0.002).

PH is associated with impaired reservoir and conduit function, but active contract function of RA is enhanced in WHO-FC Ⅱ and WHO-FC Ⅲ patients, and reduced in WHO-FCIV patients. RA LStot confers an optimal predictive effect of poor WHO-FC in PH patients and indicating prognosis.

Echocardiography; Hypertension, pulmonary; Atrial function, right; Speckle tracking imaging