Organic mitral regurgitation (MR) is a frequent heart valve disease which influences ventricular functions and impacts cardiovascular outcome. Right Ventricular Free Wall Longitudinal Strain (RVLS) is a good prognosticator in heart failure. Hence, we aimed to study its determinants in organic MR.

One hundred ninety-two patients (60±15 years, 125 males) with mild to severe chronic organic MR were prospectively enrolled and underwent a comprehensive echocardiography with RVLS assessment. RV ejection fraction (EF) was also measured by cardiac magnetic resonance (CMR) imaging (n=128) or radionuclide angiography (n=6) in 134 patients (70%) Patients were stratified into 2 groups according to RVLS≤−26% (normal function) or>−26% (RV dysfunction).

Patients with RV dysfunction exhibited a more severe condition with greater MR (SOR MR: 0.46±0.25cm² versus 0.38±0.22cm², P=0.023), were more symptomatic (NYHA 2.0±0.9 versus 1.5±0.6, P<0.0001), had a lower left ventricular global longitudinal strain (LVGLS) (−19.6±3.9% versus −21.5±2.8%, P=0.0001) and a lower RV EF by CMR/radionuclide Imaging (45.8±10% versus 50.2±7%, P=0.0037). RVLS correlated with TAPSE (r=−0.40, P<0.0001), RV Fractional shortening (r=−0.38, P<0.0001), TEI index (r=0.3, P<0.0001) and tricuspid annular systolic velocity (r=−0.27, P<0.0001). In addition, RVLS correlated only weakly (r=−0.40, P<0.0001) with RV EF. In multivariate analysis, pathophysiological determinants of RVLS were rhythm (β=−0.26, P<0.0001), pulmonary vascular resistance (Abbas formula, β=0.26, P<0.0001), LVGLS (β=0.19, P=0.01) and LV end-systolic volume (β=0.15, P=0.028).

RVLS correlates with classical echocardiographic parameters of RV function. RVLS is influenced by pulmonary vasculature resistance (ventriculo-arterial coupling) and LV function (RV to LV interdependence), in agreement with previous findings. As a simple parameter, RVLS could be added to the routine assessment of RV function in organic MR.