Radial artery spasm is one of the impediments to transradial cardiac catheterization. Although the incidence of spasm as a reason for procedural failure appears to markedly decrease with operator experience, it never completely disappears. In addition to preventing the completion of the procedure, spasm causes pain and discomfort, thereby offsetting one of the main advantages of the radial approach.
J Am Coll Cardiol Intv. 2010;3(5):484-485