Definition of Coronary Angiography

The most efficient method for evaluating and defining coronary artery disease (CAD), Coronary angiography, is used to find out the exact location and severity of CAD.

During coronary angiography, a tiny catheter is inserted through the skin into an artery usually in the groin or arm. Guided with the help of a fluoroscope (a special x-ray viewing instrument), the catheter is then taken to the opening of the coronary arteries, i.e. the blood vessels supplying blood to the heart. A little amount of radiographic contrast (a solution containing iodine, which is easily visualized with x-ray images) is then administered into each coronary artery. The images that are produced thereof are called the angiogram. Angiographic images reveal the extent and severity of all coronary arterial blockages very clearly and accurately.

Coronary angiography is carried out with the use of local anesthesia and intravenous sedation, and is only a little uncomfortable. The procedure takes around half an hour. After the procedure, the catheter is removed and the artery in the leg or arm is “sealed," or treated with manual compression so that there is no bleeding. There is a small risk of serious complications from coronary angiography, as it is an "invasive" test, but in the hands of an experienced physician, this risk is negligible.

The therapeutic information learned from the coronary angiogram is indeed far more valuable than the very little risk of the procedure. For patients with acute angina or myocardial infarction, or those who have markedly abnormal noninvasive tests for CAD, the angiogram assists the doctor to choose the best possible treatment such as coronary stenting, coronary bypass surgery, and so on.

The coronary angiogram is the only test available right now which allows correct quantification of the extent and severity of CAD to make these treatment decisions optimally.

The X-ray test that shows how the blood circulates in the arteries pumping blood to the heart is known as coronary angiogram. Your doctor will see areas where the blood vessels are narrowed or blocked.

When used

You will usually have this procedure after a stress test that shows abnormal findings. It is also used while you are on your way to the hospital for having a heart attack or unstable angina. The coronary angiogram helps spot problems in the heart arteries.

Benefits and risks 

This procedure provides crucial information about the function of the left ventricle of your heart. It also finds out blocked or narrowed coronary arteries and thus helps determine which arteries need immediate attention. This treatment might include balloon angioplasty, stenting, surgery, diet, exercise, and medicine.

The risks are as follows:

• You may feel discomfort.
• In very rare cases, you may have an allergic reaction to the drug used in the anesthesia.
• The procedure can bring about irregular heart rhythms, which could require treatment.
• If the catheter is in an artery, a blood clot could form around the catheter.
• You may be allergic to the dye. And the dye could also damage the kidneys.
• The catheter could harm a blood vessel.
• A heart attack or even stroke may be triggered by the procedure.

The risk of complications or death from this procedure is very low. People with diabetes or kidney disease might be at higher risk for kidney damage from the dye.

You are awake during the test and may sense a little pressure at the part of your body where the catheter is inserted. A flushing sensation may also occur after the dye is injected.

You may be recommended to undergo coronary angiography if:

• You have chest pain or other symptoms of coronary artery disease  
• You have increasing chest pain (unstable angina)
• You have undergone other tests that have suggested you may suffer from heart abnormalities
• You're planning to have a heart valve surgery
• You suffer from congenital heart disease
• You have congestive heart failure
• You have certain other heart or blood vessel problems or have had traumatic chest injuries

Although angiography is the universal standard for assessing coronary arteries and coronary blood flow, other imaging techniques are catching on at a fast pace.

For instance, computerized tomography - CT imaging is now used to obtain pictures of the heart arteries, thereby enabling less invasive early detection of plaque formation. CT imaging needs to use intravenous needles, but doesn't require catheterization within the heart, hence reducing risk. The main disadvantage of CT imaging is incapable of treating the heart conditions it uncovers.

"Given the low odds of survival - about 6 percent - for patients who suffer out-of-hospital cardiac arrests, it's important to understand which treatments might make a difference in these dismal outcomes," stated Jon C. Rittenberger, M.D., corresponding author of the study and an assistant professor in the Department of Emergency Medicine at the University of Pittsburgh. The importance of timely coronary angiography is always seen for cardiac arrest patients presenting with certain types of heart problems, Dr. Rittenberger noted. "But our study, which shows that angiography is independently associated with good neurologic outcomes, suggests that clinicians should consider the procedure for all post-cardiac arrest patients," he observed.

Using a contrast dye and X-rays, Coronary angiography can view the blood vessels and chambers of the heart. The procedure is usually done in conjunction with catheterization, which consists of threading a thin hollow tube through an artery and into the heart. The dye is injected into the catheter and highlights any blockages in blood flow, which are then visible by means of X-ray.

The researchers analyzed the charts of 241 adult cardiac arrest patients who were treated at UPMC Presbyterian Hospital, part of the University of Pittsburgh Medical Center, between January 1, 2005, and December 31, 2007. Coronary artery disease was found in 52 percent of the patients, and there was no difference in the rate between those who received coronary angiography (40 percent of the group) and those who did not.

If the patient is not able to exercise due to another medical condition, such as arthritis, he or she may be given a drug to mimic the effects of exercise on the heart. Some of these drugs included dipyridamole (Persantine), which dilates the coronary arteries, and dobutamine, which causes more blood flow through the heart muscle.

Patients should not drink alcoholic or caffeinated beverages, smoke tobacco, or ingest other nicotine products for 24 hours prior to the test as these substances can affect the test results. Patients should not eat anything for at least three hours before the test. They may also be instructed to stop taking certain medications during the test.

In some cases, another set of scans may be required, and the patient may be given separate instructions regarding eating and test preparation. Otherwise, the patient is free to return to his or her regular daily activities. Radioisotopes like thallium 201 should not be administered during pregnancy as they may be harmful to the fetus. A normal thallium scan depicts healthy blood flow through the coronary arteries and normal perfusion of the heart muscle, without cold spots, both at rest and during exercise. Cold spots on the scan, where no thallium can be seen, points out areas of the heart that are not getting adequate supplies of blood. Cold spots appearing both at rest and during exercise may indicate areas where the heart tissue has been damaged. However, "reversible" cold spots appearing only during exercise generally indicate some blockage of the coronary arteries.