Transradial access (TRA) has been recognized from the early days of cardiac catheterization as a safe arterial entry point. In the 1940s, Stig Radner [1] used radial cut-downs to pioneer early angiography, while Henry Zimmerman [2] and others similarly followed with success using ulnar access. Unfortunately, the forearm arteries often thrombosed after surgical repair, and once the relatively safe percutaneous approaches described by Sven Seldinger [3] and others became disseminated, the TRA was abandoned. At this time, catheters were too large, and the technology was too crude to successfully execute a cardiac catheterization without significant collateral damage, such as radial occlusion, compared to procedures done through the more significant femoral artery.