Coronary Angiogram: Uses, Procedure and Risks

Studies reveal that chronic diseases are by far the leading cause of death in the world and their impact is steadily growing. Among them, cardiovascular disease in people aged 35-64 is the leading cause. Coronary Heart Disease (CHD) is assuming large proportion in the population due to various factors like change of life styles, lack of exercise, stress, eating habits, and vices like alcohol and smoking.

As the number of deaths due to coronary heart disease is increasing by the minute, people are awakening to the fact that prevention is better than cure, and have started thinking how to safe guard themselves and take precautionary measures. Such awareness leads them to learn more about the medical terms and to gather more information and facts about such diseases. The term Coronary Angiogram has become popular even among the lay people. Therefore,  it is time to learn more about it.

Coronary means resembling or encircling like a crown and angiogram is a radiograph of blood and lymph vessels made by introducing a substance opaque to x-rays. The coronary arteries supply the heart muscle with blood.  They can become clogged from a build up of cholesterol, cells or other substances.  This can reduce the flow of blood to the heart. If a blood clot forms and completely blocks blood flow through that artery, a heart attack may occur. A coronary angiogram is a special x-ray test to find out if any coronary artery is clogged, the extent of clogging and its location. 

coronary artery block

A Coronary Angiogram is a procedure that uses x-ray imaging to see the inside of heart's blood vessels.  Coronary Angiograms are 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 the body. A coronary angiogram which helps to diagnose a heart condition, is the most common type of heart catheter procedure. During a coronary angiogram, a type of dye that is visible by the x-ray machine, is injected into the blood vessels of the heart.  The x-ray machine rapidly takes a series of images (angiogram), offering a detailed look at the inside of the blood vessels.

coronary angiogram image

The procedure of coronary angiogram is simple to understand.  The patient is given medicine to relax but he will stay awake. He then goes to the hospital's Heart Catheterization Laboratary ('cath lab').  He lies on a hard table near a camera and other equipments. The doctor numbs a spot on the groin or arm and insert a thin tube (catheter) into an artery and upto the heart. This will hurt no more like a blood test.A special  intravenous dye which contains iodine goes through the catheter so that the arteries show up well on the x-ray.  Many x-rays are taken as the dye goes through the artery.

coronary angiogram procedure

After the test the catheter will be taken out.  A nurse or doctor will apply direct pressure for 15 minutes or longer where the catheter was inserted to make sure there is no internal bleeding.  The patient will be asked to lie quietly on his back for several hours.  He would not have to lie on his back if the catheterization was performed from an arm artery.  The patient will then go back to the hospital room or Cardiac Care Unit.  The patient may feel sore where the catheter was inserted or from lying on his back.

The result of the test will show how many of the coronary arteries are blocked by fatty plaques (atherosclerosis).  It will pinpoint where blockages are located in the heart vessels.  The test will also show how much blood flow is blocked through the blood vessels. Again it will help to check the results of previous coronary bypass surgeries  and also check the blood flow through the heart and blood vessels. 
An angiogram is an invasive test and, therefore, as with most procedures done on heart and blood vessels, coronary angiogram also poses some risk. Major complications are rare, though. There is a very small risk of the catheter damaging the artery or loosening a plaque lining the artery wall. This loose piece of plaque can travel up the artery into the brain and could block blood flow causing a stroke. Some people are sensitive to the contrast agent used. The most common side effects from the iodine contrast are a brief metallic taste in the mouth and a feeling of warmth throughout the body. An extremely rare reaction occurs when the patient experiences hives and have difficulty in breathing. Medication such as antihistamines can reverse this reaction.  If the patient has diabetes or kidney problems, he may experience kidney failure, but this too is extremely rare.  The patient should tell the doctor( in the case of women), if she is pregnant.  If the patient has a history of allergies to medications, previous iodine injection, or shellfish,has diabetes, asthma, any heart conditions, kidney problems or any thyroid problems, it should be brought to the doctor's notice. The doctor should also be told if the patient is taking any blood thinning medication such as aspirin, clopidogrel (Plavix) or Coumadin.  Potential risks and implications