Two-dimensional transthoracic echocardiogram (2D TTE) from the apical 4-chamber view showing calculation of right ventricular (RV) fractional area change

Examples of right ventricular fractional area change (FAC). Percentage FAC = 100 end-diastolic area (area ED) - endsystolic area (area ES)/end-diastolic area. The endocardial border is traced in apical 4-chamber (A4C) views from the tricuspid annulus along the free wall to the apex, then back to the annulus, along the interventricular septum at end-diastole (ED) and end-systole (ES). Trabeculation, tricuspid leaflets, and chords are included in the chamber.
(A) Normal subject, FAC 60 percent.
(B) Moderately dilated right ventricle (RV), FAC 40 percent, and a markedly dilated left ventricle (LV).
(C) Dilated RV, FAC 20 percent, and the left ventricle (LV) is foreshortened as a result of optimizing the view for the right ventricular chamber.