RV Fractional Area Change (FAC) Calculator

Right Ventricular Fractional Area Change (FAC): definition, clinical meaning and evidence-based context RV FAC quantifies global right ventricular systolic function from an RV-focused apical four-chamber view by tracing the RV endocardial border in end-diastole and end-systole and applying the equation: FAC (%) = 100 × (RV end-diastolic area − RV end-systolic area) / RV end-diastolic area. The American Society of Echocardiography and contemporary echocardiography guidance recommend FAC as a validated 2-D measure that correlates with cardiac MRI-derived RV ejection fraction and is useful as part of a multiparametric RV assessment; an FAC less than 35% is generally considered abnormal and indicates impaired RV systolic function. Clinically, reduced FAC has independent prognostic implications across heart failure, pulmonary hypertension and other cardiopulmonary disease cohorts — for example, older cohort data showed that each 5% decrement in FAC was associated with a substantially increased odds of cardiovascular mortality.

FAC should not be interpreted in isolation: measurement technique (RV-focused view, careful tracing), image quality, loading conditions, and complementary RV indices (TAPSE, S′, RV free wall strain, RV size and pulmonary pressures) must be integrated for clinical decision making. For prognostic modelling, use FAC together with clinical variables and other RV metrics rather than as a single predictor to improve accuracy.