A cardiac catheterization lab nurse has the primary function of performing work using the heart catheterization tool. This catheter is inserted into the arteries of the heart and used to diagnose heart conditions and sometimes used to provide treatment for certain heart conditions. They also assist physicians with the implant of pacemakers and defibrillators in patients who are suffering from heart conditions and heart disease. Physicians performing angioplasties, valvuloplasties, stent placements, cardiac catheterization, and other catheterization procedures often employ the assistance of a cardiac catheterization lab nurse.