Effects of radiopaque material on coronary vascular reserve

The relationship between the increase in coronary blood flow (CBF) following contrast material injection and that following temporary occlusion was studied in the anesthetized dogs. The peak flow following a contrast injection was almost equivalent to the peak reactive hyperemia flow following a 10 sec occlusion (r equeals 0.86). An increase in coronary sinus blood oxygen pressure (Pcso2) occured in associated with an increase in CBF. Administration of dipyridamole diminished the increment of CBF following contrast injection with little changes in Pcso2. Thus, in the coronary system the increase in CBF after contrast injection, similar to that observed after temporary occlusion, is related to coronary vascular reserve and measurement of Pcso2 after coronary arteriography might be an aid to evaluate the coronary vascular reserve.