Assessment of Right Ventricular Contractile Patterns Using Cardiac Magnetic Resonance Imaging Would Reflect the Underlying Mechanism of Right Ventricular Dysfunction

Purpose Right ventricular (RV) function has been recognized as an important prognostic factor in patients with heart failure. However, previous studies have focused on the global RV function such as RV ejection fraction (RVEF), not on RV contractile pattern. Cardiac magnetic resonance imaging (CMR) is a powerful imaging modality to assess RV morphological change together with its global systolic function.The purpose of this study is to elucidate the difference of RV contractile patterns in various heart diseases with RV dysfunction using CMR. Methods The CMR data obtained from 50 patients with RV dysfunction and 23 control subjects were analyzed.The patients with RV dysfunction were classified into 3 groups according to the etiology of RV dysfunction; RV volume-overload group (Group V, n=16, consisting of those with atrial septal defect), RV-dominant myocyte degeneration (Group M, n=17, consisting of arrhythmogenic right ventricular cardiomyopathy), and pericarditis group (Group P, n=17). The RV longitudinal contractile pattern (FLC: fractional longitudinal change) and the radial contractile pattern (FTC: fractional transverse change) were measured using a 4-chamber view of Cine-CMR. The ratio of transverse to longitudinal contraction (T/L ratio=FTC/FLC) was calculated. Results Both FLC and FTC significantly decreased in Groups M and P, while Group V showed relatively preserved FTC compared to control subjects. The T/L ratio was significantly lower in Group M than the other groups, while the value tended to be higher in Group V and P than the control (Figure). Conclusion Impaired transverse contractile pattern as reflected by the reduced T/L ratio may indicate the degeneration of RV myocardium itself, whereas this value tends to be preserved in patients with RV dysfunction due to volume overload. RV contractile pattern may help to understand the disease progression and the underlying cause of RV dysfunction.