Changes in carotid flow velocity during catheterization of the aortic arch and common carotid artery.

Quantitative percutaneous flow velocity measurements are possible in carotid arteries by means of a directional Doppler flow velocity device and registration on a polygraph. Carotid flow velocity changes were recorded during catheterization of the ascending aorta and common carotid artery and after infusion of 20 cc contrast medium in the ascending aorta. The results indicate an increase in the flow velocity in the right common carotid artery after infusion of the contrast medium in the ascending aorta, which is thought to be attributed to a diffuse vasodilatation, at least in the cerebral circulation. The catheterization of the ascending aorta and common carotid artery seems to interfere with the common carotid flow velocity.