Right ventricular injection study in a normal dog with catheter induced tricuspid regurgitation. Note the regurgitation of the contrast material (arrow) from the right ventricle (RV) into the right atrium (RA) and RA appendage (RAA) during diastole and premature beats.

Continued right ventricular injection study in the normal dog shows right ventricular (RV) ejection of blood into the pulmonary trunk (PT) without regurgitation into the right atrium.