A new study combining animal models and human data has highlighted the concerns about the clinical reliability of commonly used echocardiographic indices for evaluating right ventricular (RV) diastolic function. The research, which involved high-fidelity pressure-volume (PV) loop analyses, suggests that standard Doppler and myocardial deformation-based metrics may not accurately reflect intrinsic RV diastolic properties or filling pressures. The research was published in Cardiovascular Ultrasound.
The study involved two cohorts: a porcine model (n=13) undergoing acute hemodynamic changes and a clinical group of patients with Fallot tetralogy or pulmonary hypertension (n=9). This dual approach enabled both within-subject and between-subject validation of echocardiographic metrics.
From PV loop data, researchers derived reference measures of RV chamber stiffness (S+), elastic recoil (S−), and relaxation constants (τ), alongside passive pressure contributions during diastole.
In the animal model, weak correlations were found between the tricuspid E/A ratio and e’ velocity with RV stiffness (Rrm 0.36 and 0.28, respectively; p < 0.01). However, these associations did not translate to the clinical cohort, where no echocardiographic index correlated with intrinsic RV diastolic mechanics.
Furthermore, while isovolumic relaxation time and early diastolic global strain rate (GSR) were moderately associated with mean right atrial pressure (RAP) (Spearman r = –0.73 and 0.85, respectively; p < 0.05), traditional indices such as E/e’ and E/GSR ratios failed to show any relationship with RAP. Tricuspid e’ and GSR also showed weak negative correlations with passive pressure at valve opening.