Reactive hyperemia: an index of the significance of coronary stenoses.

Coronary arterial stenosis of varying severity and length were created in open-chest dogs. The reactive hyperemic responses (RHR) to 15 second occlusions were used to produce flow increases and judge the physiological significance of the narrowings. RHR are sensitive indices of functional impairment when resting flow is unchanged. It was demonstrated that the length as well as the severity is important in assessing physiological significance by evaluation of narrowings 3 to 9 mm. long.