The coronary arteries supply blood to the heart muscle. They become clogged due to build up of atheromatous plaques and can reduce blood flow to the heart. If a clot blocks the blood flow it can lead to a heart attack.
An angiogram is an x-ray test that uses dye to visualize the arteries. Normally the arteries cannot be seen in an ordinary x-ray and when an iodine based dye is used as a contrast media, the arteries can be visualized. A coronary angiogram is the “gold standard” for evaluation of coronary heart disease. It is used to identify the exact location and severity of the coronary heart disease.
How is Angiogram Used to Diagnose Cardiovascular Disease?
A coronary angiogram is performed with the use of local anesthesia and intravenous sedation. Cardiac catheterization is a test used to evaluate your coronary arteries and heart valve function. It identifies the size and location of plaques that may have built up in your arteries from atherosclerosis, the strength of your heart muscle, and the adequacy of valve function. In cardiac catheterization the interventional cardiologist threads a catheter (thin flexible hollow tube of 2-3 mm) through a blood vessel in your arm or groin and into your heart. The vessels can be visualized by a fluoroscope, which is a special x-ray viewing equipment). With the catheter in place, the cardiologist can measure blood pressure, take blood samples, and inject dyes containing iodine into your coronary arteries or arteries elsewhere in your body to trace the movement of blood through the arteries and chambers of the heart. By observing the movement of the dye through your heart's chambers and blood vessels, the cardiologist can see whether the arteries are narrowed or blocked, and whether the valves are working properly. This helps determine whether you may need bypass or valve surgery or angioplasty or catheter-based valve repair.
Angiogram can look at the arteries of the heart (coronary angiogram), lung (pulmonary angiogram), brain (cerebral angiogram), head and neck (carotid angiogram), legs or arms (peripheral) and the aorta (aortogram).
An angiogram can be used to locate a bulge in a blood vessel (aneurysm) or narrowing or blockage in a blood vessel affecting blood flow.
What Does a Coronary Angiogram Show?
- Angiogram images accurately reveal the extent and severity of artery blockages including tear in a blood vessel causing internal bleeding or weaknesses in blood vessel wall (aneurysm).
- For those with severe angina or heart attack or abnormal stress tests, an angiogram is done to find out the extent and location of blockages.
- Detects changes in the blood vessels of injured or damaged organs.
Preparation For Angiogram
- All test reports, history, allergies, medication and clinical examination is done.
- Blood tests including coagulation profile, renal and liver function tests are done.
- An appointment is fixed.
- You will be asked not to eat anything for a few hours before the procedure, as a sedative is usually advised.
- You may be advised to stop anticoagulants.
- Advise on other medication will depend on your specific case
- An intravenous line will be inserted into a vein to deliver sedatives and any other medication as required.
- Electrodes will be placed on your chest to record heartbeats.
- A blood pressure monitor may be attached to your arm.
Will be done when the patient comes with an acute coronary syndrome or a heart attack.
- Following angiography, the catheter will be taken out.
- Direct pressure will be applied on the puncture site for about 10-15 minutes to make sure there is no bleeding.
- If the procedure is done by the femoral route, you will be asked to lie on your back for several hours.
- You will be observed for any bleeding at the puncture site.
- If there is no bleeding the sheath covering the puncture site will be removed.
- You will be advised to drink fluids in a short while. It may take upto 12 hours before you can resume normal work. The patient usually leaves the same day or the next day.
- Your doctor will discuss the results with you.