Right Ventricular Morphology in Patients with Left-Sided Heart Failure: Analysis Based on Cardiac Magnetic Resonance Imaging

Abstract

In a healthy subject, the left ventricle (LV) generates pressure by twisting, whereas the right ventricle (RV) dose so mainly by longitudinal shortening. Right ventricular (RV) function is recognized as a prognostic predictor in patients with left-sided heart failure. However, previous studies have focused on the global RV function such as RV ejection fraction (RVEF), not on RV morphological change.Cardiac magnetic resonance imaging (CMR) is a powerful imaging modality to assess RV morphological change which enables quantitative analysis of RV longitudinal and transverse shortening together with its global function. The purpose of this study is to investigate whether RV morphology alter even in left-sided heart failure patients with preserved RV global function. We consecutively analyzed CMR findings obtained from 143 patients with left-sided heart failure. Among those, 46 patients who were considered to have a solitary left ventricle dysfunction defined as RVEF>50% were included in the RV morphological analysis. RV-related Fractional longitudinal change (RV-FLC) and transverse change (RV-FTC) were measured. We dichotomized the patients according to the median value of RV-FLC and RV-FTC, and assessed the relationship between the RV and morphology and their LV function. Left ventricular (LV) mass was higher and the age was older in patients with low RV-FLC than in those with high RV-FLC (62.6+/-17.0 vs. 52.7+/-7.5 g/m2, p=0.018, 52.8+/-17.7 vs. 41.4+/-17.8 year-old, p=0.018, respectively). In patients with low RV-FTC, LV end-systolic volume (34.8+/-12.2 vs. 26.9+/-12.7 mL/m2 p=0.019) and RV end-systolic volume (35.8+/-8.0 vs. 28.8+/-10.1 mL/m2, p=0.006) were higher than those with high RV-FTC. In the analysis of patients showing reduced RV function (RVEF<50%), RV contractility was even more dependent on RV transverse shortening. Even in patients with left-sided heart failure and preserved RV global function, RV global function is dependent on RV transverse shortening rather than longitudinal shortening. Detailed investigation of RV contractile pattern using CMR in patients with left-sided heart failure can unveil their underlying RV dysfunction leading prognostic risk-stratification.