(MayoClinic.com) Coronary angiography is a procedure that uses X-ray imaging to examine the inside of your heart's blood vessels. It's part of a general group of procedures known as cardiac catheterization.
Catheterization refers to any procedure in which a long, thin, flexible plastic tube (catheter) is inserted into your body. Heart catheter procedures can both diagnose and treat heart and blood vessel conditions. Coronary angiography, which is used for diagnosis, is the most common type of heart catheter procedure.
During coronary angiography, a type of dye that's visible by 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 detailed look at the inside of your blood vessels.
Your doctor may recommend that you undergo coronary angiography if:
Because of its risks, angiography is usually done only after certain other heart tests have been performed, such as an electrocardiogram, an echocardiogram or a stress test.How do you prepare for coronary angiography?
Preparation is similar whether you're having coronary angiography or another type of heart catheter procedure. In some cases, these procedures are performed on an emergency basis. More commonly, though, they're scheduled in advance, giving you time to prepare.
Angiography is performed in the catheterization (cath) lab of a hospital. Usually you go to the hospital the morning of the procedure. Your health care team will give you specific instructions and talk to you about any medications you take. General guidelines include:
Before your angiography procedure starts, your health care team reviews your medical history, including allergies and medications you take. They may perform a physical exam and check your vital signs — blood pressure and pulse. You empty your bladder and change into a hospital gown. You may have to remove contact lenses, eyeglasses, jewelry, hairpins and other items.How is a coronary angiography done?
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 may move over and around your head and chest to take pictures from many angles.
An intravenous (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. 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. You may receive medication (anticoagulants) to help prevent your blood from clotting on the catheter and in your coronary arteries.
A small amount of hair may be shaved from your groin or arm where the catheter is to 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) inserted into your artery or vein. The catheter is inserted through the sheath into your blood vessel and carefully threaded to your heart or coronary arteries.
Dye (contrast material) is injected through the catheter. The dye is easy to see on X-ray images and 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 the angiography, you may have additional catheter procedures at the same time, such as a balloon angioplasty or stent placement to open up a narrowed artery.
When the angiography is over, the catheter is removed from your arm or groin and the incision is closed with a patch, clamp, manual pressure or stitches. The angiography itself takes about one hour, although it may be longer, especially if combined with other heart catheter procedures. Preparation and post-procedure care can add several more hours.What can you expect during coronary angiography?
Although you may be sedated, you'll be awake during the procedure so that you can follow instructions. Throughout the procedure you may be asked to take deep breaths, hold your breath, cough or place your arms in various positions. Your table may be tilted at times.
Threading the catheter shouldn't cause pain, and you won't feel it moving through your body. Tell your health care team if you do experience any discomfort.
When the dye is injected, you may have a brief sensation of flushing or warmth. Don't be alarmed if you feel your heart skipping beats — that's a frequent occurrence during angiograms. But again, tell your health care team if you feel pain or discomfort.
After the test
After the procedure, you're 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. During this time, pressure may be applied to the puncture site to prevent bleeding and promote healing. Sometimes, the plastic sheath that was first inserted into your blood vessel is left in place for several hours or even overnight. If you received anticoagulants during the procedure, removing the sheath too soon could trigger heavy bleeding.
You may be discharged the same day, or you may have to remain in the hospital for a day or more. 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 you can bathe or shower, return to work and resume 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 knot (hematoma).
Call your doctor's office if:
If the catheter site is actively bleeding or begins swelling, apply pressure to the site and contact emergency medical services.Results from coronary angiography
Angiography is a diagnostic tool that helps to show doctors what's wrong with your blood vessels. It can:
Knowing this can help your doctor determine your best course of treatment 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 to help unblock clogged arteries.Risks associated with coronary angiography
As with most procedures done on your heart and blood vessels, coronary angiography does pose some risk. Major complications are rare, though. Among the potential risks and complications are:
You may want to talk to your doctor about the availability of emergency cardiac surgery facilities where you're having the angiogram.Looking ahead
Although angiography remains the gold standard for assessing coronary arteries and coronary blood flow, other imaging techniques are rapidly improving and expanding.
For instance, computerized tomography (CT) imaging is now used to provide detailed pictures of the heart arteries, enabling less invasive early detection of plaque formation. Although CT imaging still requires the use of intravenous needles, it doesn't require catheterization within the heart, reducing risk. The major disadvantage of CT imaging is that it can't actually treat the heart conditions it uncovers.
Another technique gaining in popularity is magnetic resonance angiography (MRA), which is similar to the more familiar magnetic resonance imaging (MRI). MRA produces detailed images of your heart and blood vessels without the use of catheters or X-rays, although contrast dye is often injected into an arm vein. MRA works by using radio waves in a strong magnetic field to produce data that a computer turns into detailed images of tissue slices.
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