Background: To compare the effects of left ventricular volume(LV) overload due to chronic organic mitral(MR) or aortic valve(AR) regurgitation on RV shape and function.
Methods: We studied 40 patients with moderate-severe or severe primary MR (60±19 years, 52% were men) and 20 patients with moderate or severe AR (53±18 years, 81% were men). Three-dimensional echocardiography of LV and RV was performed to measure volumes and EF. RV fractional area change (FAC) was calculated and RV shape was assessed by calculating RV eccentricity index .
Results: LV end-diastolic volume (EDVi) was significantly larger in the patients with AR than those with MR. RV EF and RV FAC were lower in pts with AR than in those with MR. RV eccentricity index was significantly higher in the AR group (2.5±0.6 vs 2.1±0.5, p=0.003). In both groups, LV EDVi showed positive correlations with RV shape (RV eccentricity: r= 0.693 for AR and r=0.399 for MR; p<0.001) and negative correlations with RV function (RV EF: r= -0.545 for AR and r=- 0.383 for MR, p <0.001; RV FAC: r=-0.816 for AR and r=-0.647 for MR, p<0.001).Moreover, LV sphericity index showed negative correlations with RV function (RVFAC: r= -0.512 for MR and r=-0.608 for AR,P=0.001;RV EF:r=-0.408 for MR and r=-0.469, P=0.004) and positive correlation with the RV shape (RV eccentricity index,r= 0.39 for MR and r=0.511, P<0.001) .On multivariable linear regression analysis, LV EDVi and LV sphericity index were found to be the only independent predictors of RV eccentricity index, EF and FAC.
Conclusions: RV remodeling in chronic LV overload due to MR or AR occurs independent on PASP values. LV size and shape are the only independent predictors of RV geometry and function. Accordingly, chronic AR has a greater impact on RV than MR.