Cardiac catheterization requires placing a catheter into a blood vessel located in the neck, groin or arm and threading it to a patient's heart, according to the National Heart, Lung and Blood Institute. A physician can then perform diagnostic exams and treatments on the patient's heart through the catheter.
Additional medications are given through an intravenous line, and electrodes are placed on the patient's chest to monitor his heartbeat during the procedure, reports Mayo Clinic. Before the test begins, a nurse usually shaves the hair from the area where the catheter is going to be inserted. Patients are given an anesthetic before a physician makes a small cut to access an artery. The doctor then inserts a plastic sheath to allow the placement of the catheter.
Most cardiac catheterizations involve inserting a type of dye into the catheter and letting it flow through a patient's bloodstream to his heart, according to the NHLBI. A physician then takes X-ray photographs of the patient's heart and inspects the coronary arteries that were made visible due to the dye. Cardiologists can take heart muscle and blood samples during the procedure or perform minor heart surgery. Patients are awake during cardiac catheterization, and the procedure results in little or no discomfort aside from a slight soreness in the affected blood vessel.