The radial approach is favored for coronary angiography due of several advantages: reduction of local bleeding risk, even in the most hemorragiparic situations, decreased downtime and time reduction of hospitalization, improved patient ulterior comfort. However, this approach is subject to an immediate major complication that is the radial artery spasm (RAS) which, according to the criteria used, has an average incidence of 30%. The administration of a vasodilator just before coronary angiography procedure enables an increase of the radial artery diameter and thus a decrease of friction probes. Theoretically this prevents the occurrence of the RAS.