Right ventricular injection study in a dog with severe tricuspid regurgitation. Note regurgitation of contrast material (arrow) from the enlarged right ventricle (RV) into the right atrium (RA) and caudal vena cava (CaVC).

Continued right ventricular injection study in the dog with severe tricuspid regurgitation. Note persistent right heart opacification due to blood moving back and forth across the tricuspid valve even during the levo-phase of the cardiac cycle.