Maintained right ventricular pressure overload induces ventricular-arterial decoupling in mice.

Assessment of right ventricular (RV) function in rodents is a challenge due to the complex RV anatomy and structure. Subsequently, the best characterization of RV function is achieved by accurate cardiovascular phenotyping, involving a combination of non-invasive imaging and intra-cardiac pressure-volume measurements. We sought to investigate the feasibility of two complementary phenotyping techniques for the evaluation of RV function in an experimental mouse model of sustained RV pressure overload. Mice underwent either Sham surgery (n = 5) or pulmonary artery banding (PAB) (n = 8) to induce isolated RV pressure overload. After three weeks indices of RV function were assessed by echocardiography (Vevo2100) and closed chest-derived invasive pressure-volume measurements (PVR-1030). PAB resulted in RV hypertrophy and dilatation accompanied by systolic and diastolic dysfunction. Invasive RV hemodynamic measurements demonstrate an increased end-systolic as well as arterial elastance after PAB as compared to sham, resulting in ventricular-arterial decoupling. Regression analysis revealed that TAPSE is rather correlated with ventricular-arterial coupling (r² = 0.77, P = 0.002) than RV contractility (r² = -0.61, P = 0.07). Furthermore, IVRT/RR and E/E' correlate well with RV end-diastolic pressure (r² = 0.87, P = 0.0001 and r² = 0.82, P = 0.0009; respectively). Commonly used indices of systolic RV function are associated with RV-arterial coupling rather than contractility, while diastolic indices are interrelated with end-diastolic pressure where there is maintained pressure overload. This article is protected by copyright. All rights reserved.