Angiogram: What is it? Why is it Performed?

An angiogram, also called a coronary angiogram, is a procedure, which involves the use of X-rays to view the blood vessels of the heart. It is a diagnosticmethod that is generally performed to check if there is any restriction inthe flow of blood through the cardiac blood vessels.

A coronary angiogram is a part of a group of medical procedures known as cardiac catheterization. The cardiac catheterization procedures can help in the diagnosis as well as the treatment of the conditions affecting the heart and blood vessels. A coronary angiogram is one of the most commonly performed cardiac catheterization procedures.

During an angiogram, a dye visible through an X-ray machine is administered into the blood vessels of the heart of the patient in the form of an injection. The X-ray machine then takes a series of angiograms that offer a view of the blood vessels.

The doctor may also perform angioplasty to open the clogged heart arteries during a coronary angiogram, when necessary.

Why is an angiogram done?

The common indications for a coronary angiogram include:

  • Having symptoms or risk of coronary artery diseases, such as chest pain (angina) or medical history of hypertension
  • Abnormal results of a non-invasive test such as a treadmill stress test
  • Pain in the chest, jaw, arm, or neck whose cause cannot be detected by other tests
  • Having congenital heart disease (a heart defect the patient was born with)
  • Unstable angina with new or worsening chest pain
  • Chest injury
  • Conditions affection the blood vessels
  • A condition affecting the heart valves that requires surgery

Due to the small risk of complications, an angiogram is not performed as a part of the routine cardiac assessment. It is often reserved for patients in whom non-invasive tests such as an echocardiogram, an electrocardiogram, and a stress test have failed to provide a conclusive diagnosis.

Doctors can attend our AARC Approved CEUs to learn the indications for a coronary angiogram and how this test can help in the diagnosis of several diseases.

What are the risks involved in an angiogram?

As with most medical procedures performed on the heart and blood vessels, an angiogram also has some risks, like exposure to radiation due to the X-rays used.

Hence, it is important to assess the patient for the possible risks based on his or her general health, symptoms, and pre-existing health conditionsbefore an angiogram.

Some potential risks and complications of an angiogram include:

  • Heart attack
  • Injury to the catheterized artery
  • Stroke
  • Allergic reaction to the medications or dyes used during the procedure
  • Arrhythmias (irregular heart rhythms)
  • Renal damage
  • Infection
  • Excessive bleeding

Careful assessment of the patient is essential for preventing the risk of complications of an angiogram. Our AARC Approved CEUs for doctors can provide comprehensive guidance about the indications for an angiogram and the right way to perform this procedure in order to avoid complications.

How to prepare for an angiogram?

An angiogram is performed in the catheterization laboratory in a healthcare setting. In most cases, a coronary angiogram is performed on an emergency basis. In some cases, it is planned in advance, giving the patients time to prepare.

The healthcare team should talk to the patient or his or her family member and give specific instructions they need to take before and after the procedure.

Some general guidelines to prepare for an angiogram include:

  • The patients should not eat or drink anything for 10 hours before the angiogram.
  • They should carry all the regular medications to the hospital.
  • The doctor should check all the medications used by the patients and advise on whether they shouldtake the regular doses on or before the day of the procedure.

How is an angiogram performed?

During the procedure, the patient is asked to lie on the back on an X-ray table. Then, X-ray cameras move over and around the patient's head and chest to take pictures from several angles.

A sedative can be administered through an IV line inserted into the vein of the patient's arm to help him relax. Other medications and fluids can also be given through the IV line.

Then, the electrodes are applied to the chest to monitor the heart throughout the procedure. A blood pressure cuff is tied to one arm to track the blood pressure while another device called a pulse oximeter measures the oxygen level in the blood.

Then, a small incision is made on the skin through which a plastic tube is inserted into the blood vessel. The catheter is threaded carefully towards the heart.

A small amount of dye is injected through the catheter. The dye allows the blood vessels to be viewed on the X-ray images. As the dye moves through the blood vessels, the doctor can control its flow and identify any constricted areas or blockages.

The doctor may also perform additional catheter procedures during the angiogram, like balloon angioplasty and stent placement to open the narrow artery.

After the angiogram, the catheter is removed and the incision is closed with a clamp or manual pressure.

The patient is taken to a recovery area for monitoring and observation. When the patient's condition is stable, he or she can be returned to the room for further monitored.

An angiogram takes about 40 to 60 minutes. It may take longer when it is combined with any other cardiac catheterization procedure.

Results of an angiogram

An angiogram can help the doctors view the abnormalities in the blood vessels. It can help to assess how many coronary arteries are narrowed or blocked by fatty plaques and pinpoint the blockages located in the blood vessels. This test can also help to evaluate the results of previous bypass surgery.


The result of an angiogram can help doctors decide the best treatments to improve the patients’ symptoms.  Doctors and nurses can attend our Respiratory Therapy Continuing Education CEUs to learn the right ways to perform this procedure, its indications, and the precautions to be taken to avoid complications.