Coronary circulation after suppression of barorecptor reflexes (preliminary observations)

In five anaesthetized open-chest dogs, aortic blood pressure, cardiac output and coronary flow were recorded. After the barorecptor reflex activity was suppressed by clamping both common carotid arteries and cutting both vagi nerves, aortic blood pressure and mean coronary flow increased. Phasic coronary flow further decreased in systole and increased in diastole, whereas coronary vascular resistance fell only when the suppression of the baroreceptor reflex activity had caused an increase of the heart rate.