When receiving a heart catheter, a patient is requested to lie on his back while the doctor numbs the area on the neck, groin or arm where the catheter is to be inserted into the blood vessel, explains the National Heart, Lung and Blood Institute. The doctor makes a small hole in the blood vessel using a needle, and then inserts a sheath before putting a flexible guide wire through the tube into the blood vessel to reach the heart.
When the catheter reaches the correct spot, the doctor uses it for treatments or does tests on the patient’s heart, explains the National Heart, Lung and Blood Institute. In order to determine the right spot to put the tip of the catheter, special X-ray movies are taken of the catheter and the guide wire as they are moved into the heart. During the procedure, the doctor may use a special type of dye that flows through the bloodstream to the heart, making the coronary arteries visible on the X-ray pictures. After the needed treatments or tests are performed, the doctor pulls back the catheter along with the sheath, closing up and bandaging the opening left in the blood vessel.
Cardiac catheterization is conducted in a operating room with imaging machines, explains WebMD. It is performed while the patient is awake, but numb.