Coronary angiography uses X-ray imaging to examine the inside of your heart's blood vessels and the procedure is called cardiac catheterization. A long, thin, flexible plastic tube (catheter) is inserted selectively into your coronary artery. A type of dye that's visible by X-ray machine is injected and it rapidly takes a series of images (angiograms), offering a detailed picture of the arteries showing any narrowing or blocks.
Indication for Coronary Angiogram
Coronary angiography is usually recommended for the following reasons:
If you have symptoms of chest pain (Angina).
Unexplained pain in your chest, jaw, neck or arm, and other tests has been inconclusive.
If you have increasing or new chest pain (unstable angina).
Other tests like ECG have suggested you may have heart abnormalities.
If you're going to have surgery unrelated to your heart, but you're at high risk of having a heart problem during that surgery.
If you have congenital heart disease.
If you're planning to have heart valve surgery.
If you have congestive heart failure.
Preparation for coronary angiography
Angiography is performed in the catheterization (cath) lab of the hospital.
No food or drink after midnight, the day before your procedure.
Bring all your medications to the hospital with you. Ask your doctor about whether or not to take your usual morning medications.
Diabetic patients should discuss your insulin or oral medication program with your doctor.
The staff reviews your medical history, including allergies and medications you take. They do physical exam and check your vital signs — blood pressure and pulse. You empty your bladder and change into a hospital gown. Usually contact lenses, eyeglasses, jewelry, and other items are removed.
The Procedure
The Patient lie on his/her back on an X-ray table. The X-ray cameras move over and around the head and chest to take pictures from many angles. Usually an intravenous (IV) line is inserted into a vein in your arm so that drugs may be given during the procedure if required. Electrodes on your chest monitor your heart throughout the procedure. A blood pressure cuff checks your blood pressure and a special device - pulse oximeter, measures the amount of oxygen in your blood.
The groin or arm is prepared by shaving a bit and cleaning with disinfectant where the catheter is to be inserted. The area is 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 coronary arteries. Dye (contrast material) is injected through the catheter and any blockages or constricted areas are visualized. Depending on the angiogram the doctor may decide on additional catheter procedures at the same time, such as a balloon angioplasty or stent placement to open up the narrowed artery.
When the angiography is over, the catheter is removed from your arm or groin and manual pressure applied to ensure there is no bleeding. The angiography itself takes about 30 minutes although it may be longer, especially if angioplasty and stenting is carried out. You'll be awake during the procedure. Threading the catheter shouldn't cause pain, and you won't feel it moving through your body.
After the test
After the procedure, you return to your ward, where you're monitored regularly. You'll need to lie flat for few hours to avoid bleeding. During this time, pressure may be applied to the puncture site to prevent bleeding and promote healing. The plastic sheath that was first inserted into your blood vessel is left in place for about four hours or even overnight. If you received anticoagulants during the procedure, removing the sheath too soon could trigger 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. Avoid strenuous activities and heavy lifting for few days. Your puncture site is likely to remain tender for a while. It may be slightly bruised.
Results from coronary angiography
Show how many coronary arteries are blocked.
Show where blockages are located in your blood vessels.
Indicate the extent of blockages.
Assess blood flow through your heart and blood vessels.
This determines the best course of treatment. Your doctor may decide, for instance, that you would benefit from having coronary angioplasty to help unblock clogged arteries.
Complications of coronary angiography
Major complications are rare, potential risks are: