Effusion | | | |
Pericardial effusion | Easy to perform, relevant for follow-up [14] | Can be useful as a supplement to echo [15] | NA |
Pressure | | | |
PAP | Estimation of PAP based on TRV; some controversy versus invasive techniques, and pitfalls have been described, e.g. false interpretation of the spectral wave envelope, sweep velocity set too slow and valve closure artefacts [16] | NA | Fundamental measurement for distinguishing PAH from other forms of PH [7, 17] |
Anatomy | | | |
Right atrial area | Reference values for right atrial area in healthy adult subjects have been described [18]; easy to perform, accurate | Reference values for right atrial area in healthy adult subjects have been described [19] | NA |
RV area | Ethnicity, sex and training effects (Asians and females have smaller RV area, sportsmen have higher area [20]); not useful for screening; high variation, even in healthy subjects | Considered the gold standard for measuring ventricular volume, mass and structure [21] | NA |
RV mass | NA | NA |
RV dimensions | RV basal, mid-cavity and longitudinal dimensions on a four-chamber view should be measured in patients with PH [22]; high variation | NA |
RV wall thickness | RV thickness can be assessed; thickness >5 mm may suggest RV pressure overload in the absence of other pathologies [22] | Can be measured directly through evaluation of RV mass [23], or indirectly based on the need for increased myocardial perfusion [21] | NA |
Eccentricity index | Predictive of poor outcomes [24] | NA | NA |
Central pulmonary artery diameter | Reference values have not been determined | NA | NA |
Function | | | |
RVEF | Three-dimensional echo is more accurate and reproducible than two-dimensional echo [13] | Can be calculated retrospectively from the stroke volume divided by the end-diastolic volume [25] | NA |
TAPSE | Directly measures RV function; does not require post hoc analyses or expertise to measure [26] | NA | NA |
Tei index (RV myocardial performance index) | Calculated as the sum of RV isovolumetric contraction time/ejection time and isovolumetric relaxation time/ejection time [27] | NA | NA |
RV end-systolic elastance, arterial elastance | NA | CMRI-derived indices have been combined with RHC variables to determine right ventriculo–arterial coupling [28] | NA |