Diastolic interventricular septal flattening in right ventricular volume overload

Parasternal short-axis transthoracic echocardiographic views of the left ventricle (LV) and right ventricle (RV) in a patient with RV volume overload and anasarca.
(A) View at end-diastole. The RV is markedly dilated. The LV should normally be circular in this view, with the interventricular septum concave toward the LV. However the interventricular septum is flattened by volume overloading of the RV within a constraining pericardium. This septal flattening is maximal when the RV is maximally distended, at end-diastole.
(B) View at end-systole. Note that the interventricular septum which was flattened at end-diastole (A), recovers its normal curvature and concavity toward the LV at end-systole.