#POCUS #Nephpearls #FOAMed The RV should normally appear smaller than the LV in the apical 4-chamber view and should not exceed about two-thirds of the LV size. If the RV appears equal to or larger than the LV, significant RV dilation should be suspected. Another helpful visual clue is when the RV becomes the apex-forming ventricle instead of LV. While this finding has not been formally validated with quantitative thresholds, it generally suggests at least moderate RV dilation. If you remember just one measurement, remember this: the upper limit of normal RV basal diameter is 4.2 cm, measured at end-diastole in an RV-focused apical 4-chamber view. Also assess RV wall thickness. An RV end-diastolic free wall thickness >5 mm (typically measured in the subcostal view) indicates RV hypertrophy, which often accompanies chronic pressure overload and RV dilation. Finally, don’t forget to look for interventricular septal flattening on the parasternal short-axis view. Septal flattening (“D-shaped” LV) is another important clue to RV pressure and/or volume overload.