Right atrial size and function in patients with pulmonary hypertension associated with disorders of respiratory system or hypoxemia

Background and aim: Pulmonary hypertension (PH) determines various adaptive changes in right ventricular (RV) geometry which may progressively lead atrium (RA) is theoretically involved in this physiopathotogical process, but its role has never been investigated. We hypothesized that RA increases volume and function to assist RV during the chronic pressure overload exposition due to PH. Methods: We prospectively enrolled 66 consecutive patients referred to our echolab with a diagnosis of PH [defined as pulmonary artery systolic pressure (PASP) > 30 mmHg] associated with disorders of the respiratory system and/or hypoxemia and normal RV systolic function. Ejection force was taken up as index of RA systolic function and calculated according to the Manning's formula. Thirty-three healthy subjects for whom PH was definitely excluded by echoDoppler evaluation were used as controls. Results: PASP was 42 10 and 20 8 mmHg in PH patients and controls, respectively; p = 0.00001). In comparison with controls, PH patients exhibited higher RA volume (37 +/- 13 vs 32 +/- 13 ml, p = 0.04) and RA ejection force (6.7 +/- 3.0 vs 3.5 +/- 1.8 Kdynes, p = 0.00001). Both variables were positively related to PASP (r = 0.23 and 0.48, p = 0.02 and 0.00001, respectively).