Association with right atrial strain with right atrial pressure: an invasive validation study

Echocardiographic assessment of right atrial pressure (RAP) from inferior vena cava (RAP_IVC) dimension may underestimate catheter-derived (RAP_C). As right atrial (RA) deformation, measured by speckle tracking, is preload-dependent, we hypothesized that RA strain may improve estimation of RAP_C. Right atrial strain components [RA reservoir function (ƐR), peak RA contraction (ƐCT) and RA conduit function (ƐCD)] were measured in 125 of 175 patients who had echocardiography and invasive measures of RAP (median difference 1 day). To determine whether RA strain measures differentiated patients with correct vs incorrect RAP_IVC assessment, categories with RAP_IVC values < 3, 8 and > 15 mmHg were compared with RAP_C groups < 3, 4-7, 8-10, 11-14 and > 15 mmHg. Non-invasively determined RAP was significantly lower (p = 0.001) than invasively determined RAP_C, with a weak correlation (r = 0.35, p < 0.001). RA strain components were associated with RA size, RV function and IVC size. In those with RAP_IVC > 15 mmHg, half of patients were categorized into RAP < 10 mmHg. There were no significant differences in RA characteristics that differentiated patients in whom echocardiographic estimation of RAP was inaccurate. Right atrial strain measures were feasible, and had associations with RA size, RV systolic function and IVC size. Right atrial strain was significantly different between those with normal vs raised pressure, but it did not identify those with incorrect echocardiographic assessment of RAP.