Medically reviewed by Drugs.com. Last updated on Dec 14, 2021.
A coronary angiogram is a procedure that uses X-ray imaging to see your heart's blood vessels. The test is generally done to see if there's a restriction in blood flow going to the heart.
Coronary angiograms are part of a general group of procedures known as heart (cardiac) catheterizations. Cardiac catheterization procedures can both diagnose and treat heart and blood vessel conditions. A coronary angiogram, which can help diagnose heart conditions, is the most common type of cardiac catheterization procedure.
During a coronary angiogram, a type of dye that's visible by an X-ray machine is injected into the blood vessels of your heart. The X-ray machine rapidly takes a series of images (angiograms), offering a look at your blood vessels. If necessary, your doctor can open clogged heart arteries (angioplasty) during your coronary angiogram.
Why it's done
Your doctor may recommend that you have a coronary angiogram if you have:
- Symptoms of coronary artery disease, such as chest pain (angina)
- Pain in your chest, jaw, neck or arm that can't be explained by other tests
- New or increasing chest pain (unstable angina)
- A heart defect you were born with (congenital heart disease)
- Abnormal results on a noninvasive heart stress test
- Other blood vessel problems or a chest injury
- A heart valve problem that requires surgery
Because there's a small risk of complications, angiograms aren't usually done until after noninvasive heart tests have been performed, such as an electrocardiogram, an echocardiogram or a stress test.
As with most procedures done on your heart and blood vessels, a coronary angiogram has some risks, such as radiation exposure from the X-rays used. Major complications are rare, though. Potential risks and complications include:
- Heart attack
- Injury to the catheterized artery
- Irregular heart rhythms (arrhythmias)
- Allergic reactions to the dye or medications used during the procedure
- Kidney damage
- Excessive bleeding
How you prepare
In some cases, coronary angiograms are performed on an emergency basis. More commonly, though, they're scheduled in advance, giving you time to prepare.
Angiograms are performed in the catheterization (cath) lab of a hospital. Your health care team will give you specific instructions and talk to you about any medications you take. General guidelines include:
- Don't eat or drink anything after midnight before your angiogram.
- Take all your medications to the hospital with you in their original bottles. Ask your doctor about whether to take your usual morning medications.
- If you have diabetes, ask your doctor if you should take insulin or other oral medications before your angiogram.
What you can expect
Before the procedure
Before your angiogram procedure starts, your health care team will review your medical history, including allergies and medications you take. The team may perform a physical exam and check your vital signs — blood pressure and pulse.
You'll also empty your bladder and change into a hospital gown. You may have to remove contact lenses, eyeglasses, jewelry and hairpins.
During the procedure
For the procedure, you lie on your back on an X-ray table. Because the table may be tilted during the procedure, safety straps may be fastened across your chest and legs. X-ray cameras will move over and around your head and chest to take pictures from many angles.
An IV line is inserted into a vein in your arm. You may be given a sedative through the IV to help you relax, as well as other medications and fluids. You'll be very sleepy and may drift off to sleep during the procedure, but you'll still be able to be easily awakened to follow any instructions.
Electrodes on your chest monitor your heart throughout the procedure. A blood pressure cuff tracks your blood pressure and another device, a pulse oximeter, measures the amount of oxygen in your blood.
A small amount of hair may be shaved from your groin or arm where a flexible tube (catheter) will be inserted. The area is washed and disinfected and then numbed with an injection of local anesthetic.
A small incision is made at the entry site, and a short plastic tube (sheath) is inserted into your artery. The catheter is inserted through the sheath into your blood vessel and carefully threaded to your heart or coronary arteries.
Threading the catheter shouldn't cause pain, and you shouldn't feel it moving through your body. Tell your health care team if you have any discomfort.
Dye (contrast material) is injected through the catheter. When this happens, you may have a brief sensation of flushing or warmth. But again, tell your health care team if you feel pain or discomfort.
The dye is easy to see on X-ray images. As it moves through your blood vessels, your doctor can observe its flow and identify any blockages or constricted areas. Depending on what your doctor discovers during your angiogram, you may have additional catheter procedures at the same time, such as a balloon angioplasty or a stent placement to open up a narrowed artery. Other noninvasive tests, such as ultrasound, may help your doctor evaluate identified blockages.
Having an angiogram takes about one hour, although it may be longer, especially if combined with other cardiac catheterization procedures. Preparation and post-procedure care can add more time.
After the procedure
When the angiogram is over, the catheter is removed from your arm or groin and the incision is closed with manual pressure, a clamp or a small plug.
You'll be taken to a recovery area for observation and monitoring. When your condition is stable, you return to your own room, where you're monitored regularly.
You'll need to lie flat for several hours to avoid bleeding if the catheter was inserted in the groin. During this time, pressure may be applied to the incision to prevent bleeding and promote healing.
You may be able to go home the same day, or you may have to remain in the hospital overnight. Drink plenty of fluids to help flush the dye from your body. If you're feeling up to it, have something to eat.
Ask your health care team when to resume taking medications, bathing or showering, working, and doing other normal activities. Avoid strenuous activities and heavy lifting for several days.
Your puncture site is likely to remain tender for a while. It may be slightly bruised and have a small bump.
Call your doctor's office if:
- You notice bleeding, new bruising or swelling at the catheter site
- You develop increasing pain or discomfort at the catheter site
- You have signs of infection, such as redness, drainage or a fever
- There's a change in temperature or color of the leg or arm that was used for the procedure
- Weakness or numbness in the leg or arm where the catheter was inserted
- You develop chest pain or shortness of breath
If the catheter site is actively bleeding and doesn't stop after you've applied pressure to the site, contact 911 or emergency medical services. If the catheter site suddenly begins to swell, contact 911 or emergency medical services.
In a cardiac catheter procedure, a health care provider inserts a catheter in an artery in the wrist (radial artery) or in the groin (femoral artery). The catheter is then threaded through the blood vessels to the heart.
An angiogram can show doctors what's wrong with your blood vessels. It can:
- Show how many of your coronary arteries are blocked or narrowed by fatty plaques (atherosclerosis)
- Pinpoint where blockages are located in your blood vessels
- Show how much blood flow is blocked through your blood vessels
- Check the results of previous coronary bypass surgery
- Check the blood flow through your heart and blood vessels
Knowing this information can help your doctor determine what treatment is best for you and how much danger your heart condition poses to your health. Based on your results, your doctor may decide, for instance, that you would benefit from having coronary angioplasty or stenting to help clear clogged arteries. It's also possible that angioplasty or stenting could be done during your angiogram to avoid needing another procedure.