The echocardiographic assessment of the RV
The challenges in the echocardiographic evaluation of the RV come from its complex geometry, its position behind the sternum, its trabeculations which make endocardial tracing cumbersome, as well as from its dependence on hemodynamic load and interdependence with the LV. In fact, some authors suggest that up to 20-40% of RV stroke volume result from the contraction of the LV [14]. There is no ideal echocardiographic parameter for quantification of RV performance [15], hence a thorough echocardiographic evaluation needs an integrative, multi-parametric approach from multiple acoustic windows, as suggested by current guidelines [16].
Conventional parameters assessing RV systolic function are tricuspid annular plane systolic excursion (TAPSE), tricuspid lateral annular systolic velocity (S’ wave) derived from tissue Doppler imaging (TDI), RV isovolumic acceleration, RV fractional area change (FAC), while RV myocardial performance index (MPI) is a marker of global RV function. Innovative parameters for the assessment of the RV performance are derived from bidimensional (2D) speckle tracking echocardiography (STE) (such as RV global strain and strain rate, as well as RV free wall strain and strain rate), from 3D echocardiography (such as 3D RVEF) and – more recently – from 3D STE.