Transverse and longitudinal right ventricular fractional parameters derived from four-chamber cine MRI are associated with right ventricular dysfunction etiology

Studies of the usefulness of transverse right ventricular (RV) shortening are limited. We retrospectively analyzed the CMR images of 67 patients (age: 50.8 ± 19.0 years; men: 53.7%; Control: n = 20, Overloaded RV (atrial septal defect): n = 15, Constricted RV (pericarditis): n = 17, Degenerated RV (arrhythmogenic right ventricular cardiomyopathy): n = 15) (all enrolled consecutively for each disease) in a single center. We defined RV longitudinal (fractional longitudinal change: FLC) and transverse (fractional transverse change: FTC) contraction parameters. We assessed the FTC/FLC (T/L) ratio on four-chamber cine CMR views and compared the four groups regarding the fractional parameters. FTC had a stronger correlation (R(2) = 0.650; p < 0.001) with RV ejection fraction than that with FLC (R(2) = 0.211; p < 0.001) in the linear regression analysis. Both FLC and FTC were significantly lower in the Degenerated RV and Constricted RV groups compared with those in the Control and Overloaded RV groups. The T/L ratio was significantly lower in the Degenerated RV group (p = 0.008), while the Overloaded RV (p = 0.986) and Constricted RV (p = 0.582) groups had preserved T/L ratios, compared with the Control group. Transverse shortening contributes to RV function more significantly compared with longitudinal contraction. Impaired T/L ratios may reflect RV myocardial degeneration. RV fractional parameters may help precisely understand RV dysfunction.