Cardiac catheterization is done in a hospital. During the procedure, you'll be kept on your back and awake. This allows you to follow your doctor's instructions during the procedure. You'll be given medicine to help you relax, which might make you sleepy.
Your doctor will numb the area on the arm, groin (upper thigh), or neck where the catheter will enter your blood vessel. Then, a needle will be used to make a small hole in the blood vessel. Your doctor will put a tapered tube called a sheath through the hole.
Next, your doctor will put a thin, flexible guide wire through the sheath and into your blood vessel. He or she will thread the wire through your blood vessel to your heart.
Your doctor will use the guide wire to correctly place the catheter. He or she will put the catheter through the sheath and slide it over the guide wire and into the coronary arteries.
Special x-ray movies will be taken of the guide wire and the catheter as they're moved into the heart. The movies will help your doctor see where to put the tip of the catheter.
The animation below shows the process of cardiac catheterization. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.
The animation shows the step-by-step process your doctor will follow to do cardiac catheterization.
During the procedure, your doctor may put a special type of dye in the catheter. The dye will flow through your bloodstream to your heart. Then, your doctor will take x-ray pictures of your heart. The dye will make your coronary (heart) arteries visible on the pictures. This test is called coronary angiography.
Coronary angiography can show how well the heart's lower chambers, called the ventricles (VEN-trih-kuls), are pumping blood.
When the catheter is inside your heart, your doctor may use it to take blood and tissue samples or do minor heart surgery.
To get a more detailed view of a blocked coronary artery, your doctor may do intracoronary ultrasound. For this test, your doctor will thread a tiny ultrasound device through the catheter and into the artery. This device gives off sound waves that bounce off the artery wall (and its blockage). The sound waves create a picture of the inside of the artery.
If the angiogram or intracoronary ultrasound shows blockages in the coronary arteries, your doctor may use angioplasty to treat the blocked arteries.
After your doctor does all of the needed tests or treatments, he or she will pull back the catheter and take it out along with the sheath. The opening left in the blood vessel will be closed up and bandaged.
A small weight might be put on top of the bandage for a few hours to apply more pressure. This will help prevent major bleeding from the site.