Evaluating the effect of ulnar artery compression while pressing on radial artery to stop bleeding, in maintaining radial artery potency, after cardiac catheterization through the radial artery. We prospectively plan to compare 3000 patients referred for cardiac catheterization, randomized into two groups, one group receiving radial artery compression for stopping bleeding, in a standard fashion following best practices, and the other group receiving radial artery compression using standard best practices and ulnar artery compression. Radial artery status will be evaluated in 24 hours and 30 days of the procedure to evaluate its potency, using plethysmography.

Inclusion Criteria:

• patients referred for diagnostic cardiac catheterization.

Exclusion Criteria:

• previous ipsilateral radial artery puncture, warfarin therapy, absence of intact palmar collateral circulation, scleroderma, ipsilateral radial artery surgery, lone upper extremity (contralateral upper extremity amputation), ipsilateral upper extremity chronic pain.