The derivation of coronary sinus flow during elevation of right ventricular pressure.

The derivation of coronary sinus flow during increased pulmonary and right ventricular pressures was resubmitted to experimental study. The primary reduction and subsequent augmentation in coronary flow following pulmonary artery constriction and the persistence of a greater flow after release preclude the concept of a variable contribution via thebesian channels from the right ventricular cavity. When the magnitude of the increase is also considered, it is difficult to escape the conclusion that drainage from the right ventricle is also involved. The use of coronary sinus blood in studies of metabolism of the left ventricle under various dynamic conditions seems precarious.