Fractional -SFD in control subjects and PH patients, for seven longitudinal levels in the RV, from apex (level 1) to base (level 7). Fractional-TAAD is shown on the right. In patients, the RV exhibits for each ventricular level approximately the same fractional-SFD. In contrast, control subjects show the highest fractional-SFD around the apex, with less fractional-SFD around the base. For every longitudinal level, differences in fractional change between controls and patients were significant with p < 0.0001. A = Apex, T = lateral annulus of tricuspid valve, S = RV endocardial septum, F = RV endocardial free wall.