Figure 3.

Assessment of RV size and fractional area change (FAC). From the RV-focussed apical 4-chamber window, a contour should be traced from the lateral tricuspid annulus along the free wall to the apex, and back along the interventricular septum to the medial tricuspid valve annulus. This should be undertaken at end-diastole (left panel), and the area indexed to BSA, providing us with indexed RV end-diastolic area. This process can be repeated in end-systole (right panel), from which we can derive the FAC as follows: FAC = (RVA diastole − RVA systole)/RVA diastole × 100%.