Relation of Tissue Displacement and Strain to Invasively Determined Right Ventricular Stroke Volume

The role of echocardiography in the clinical assessment of right ventricular (RV) systolic function remains limited. Limited data exist on the potential use of newer techniques for RV function assessment. Conventional echocardiography and tissue Doppler echocardiography (TDE) were performed during right-sided cardiac catheterization in 46 patients. Thermodilution or the Fick-derived RV stroke volume indexed (RVSVI) indexed to body surface area was used as the reference standard. Univariate and multivariate regression analyses were used to test correlations between RVSVI and various echocardiographic and TDE-derived parameters. In a subset of 12 subjects, changes in echocardiographic and TDE variables to reduced afterload from intravenous epoprostenol were measured. TDE-derived RV tissue displacement and systolic strain best predicted the RVSVI (r = 0.63, p = 0.001; r = 0.48, p = 0.002, respectively). The prediction improved after adjustment for tricuspid regurgitation jet vena contracta width (r = 0.74, p < 0.0001; r = 0.60, p < 0.001, respectively). Assuming a RVSVI of > or =30 ml/m(2) as normal, a RV displacement cutoff of 15 mm yielded a sensitivity of 100% and a specificity of 41% for RV dysfunction, and an RV systolic strain cutoff of 20% yielded a sensitivity of 91% and a specificity of 63%. The percentage change of RV systolic displacement correlated well with the percentage change of RVSVI after epoprostenol infusion (r = 0.75, p < 0.001). In conclusion, TDE-derived RV displacement and strain closely correlate with RVSVI and appropriately track load-related changes in RV function. These new parameters may help provide the noninvasive, quantitative assessment of RV function.