Cardiac angiography; Angiography - heart; Angiogram - coronary; Coronary artery disease - angiography; CAD - angiography; Angina - angiography; Heart disease - angiography
Coronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart.
How the Test is Performed
Coronary angiography is sometimes performed with cardiac catheterization. This is a procedure that measures pressures in the heart chambers.
Before the test starts, you will be given a mild sedative to help you relax.
An area of your body (the arm or groin) is cleaned and numbed with a local numbing medicine (anesthetic). The cardiologist passes a thin hollow tube, called a catheter, through an artery and carefully moves it up into the heart. X-ray images help the doctor position the catheter.
Once the catheter is in place, dye (contrast material) is injected into the catheter. X-ray images are taken to see how the dye moves through the artery. The dye helps highlight any blockages in blood flow.
The procedure most often lasts 30 to 60 minutes.
How to Prepare for the Test
You should not eat or drink anything for 8 hours before the test starts.
You will wear a hospital gown. You must sign a consent form before the test. Your health care provider will explain the procedure and its risks.
Tell your provider if you:
- Are allergic to any medicines or if you have had a bad reaction to contrast material in the past
- Are taking sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis) or other medicines from this class
- Might be pregnant
How the Test will Feel
In most cases, you will be awake during the test. You may feel some pressure at the site where the catheter is placed.
You may feel a flushing or warm sensation after the dye is injected.
After the test, the catheter is removed. You might feel a firm pressure being applied at the insertion site to prevent bleeding. If the catheter is placed in your groin, you will be asked to lie flat on your back for a few hours to several hours after the test to avoid bleeding. This may cause some mild back discomfort.
Why the Test is Performed
Coronary angiography may be done if:
- You have angina for the first time.
- Your angina that is becoming worse, not going away, occurring more often, or happening at rest (called unstable angina).
- You have aortic stenosis or another valve problem.
- You have atypical chest pain, when other tests are normal.
- You had an abnormal heart stress test.
- You are going to have surgery on your heart and you are at high risk for coronary artery disease.
- You have heart failure.
- You have been diagnosed as having a heart attack.
Cardiac catheterization and coronary angiography are most commonly performed to diagnose and examine the severity of coronary artery disease. They are the gold standard for diagnosing coronary artery disease. Coronary artery disease is caused by narrowing or blockage of the coronary arteries due to the formation of atherosclerotic plaques in the walls of these arteries, thus restricting blood flow to cardiac muscle. Coronary artery disease is the main cause for angina, myocardial infarction (or heart attack), and heart failure. Coronary artery disease must be present in varying degrees in all three of the clinical diagnoses of acute coronary syndrome (ACS). Patients present in one of three ways: unstable angina, myocardial infarction without ST segment elevation (NSTEMI), and myocardial infarction with ST segment elevation (STEMI). In patients with congestive heart failure and left ventricular dysfunction, cardiologists use cardiac catheterization to obtain critical information on the condition of the heart, and therefore, decide on appropriate therapeutic interventions. In congestive heart failure, the heart fails to pump blood adequately to maintain blood circulation in the body. This results in congestion of blood, and therefore, edema in tissues of the body, such as, in the lungs, liver, feet, and ankles. Liver congestion is a large part of congestive heart failure as well. Left ventricular dysfunction refers to a condition where there is decreased movement of the left ventricle, resulting in dilation of the ventricle and weakening of the cardiac muscle. Left ventricular dysfunction may progress into congestive heart failure. Cardiac catheterization can help cardiologists evaluate the underlying cause of symptoms associated with left ventricular dysfunction and congestive heart failure, measure the extent of dysfunction in the left ventricle, measure the pressures inside the right side of the heart to evaluate fluid status, and measure cardiac output. Cardiac catheterization is also indicated for patients with myocardial infarction. Myocardial infarction refers to damage and death to an area of the myocardium, usually caused by coronary artery disease. Cardiac catheterization allows cardiologists to assess the extent of damage caused to the heart muscle, and to decide on a therapeutic approach for the underlying cause of the infarction. Cardiac catheterization may be also used to evaluate patients with cardiomyopathies. Cardiomyopathies refer to a group of diseases, with or without a known cause, that primarily affect cardiac muscle function. In patients with valvular heart disease, cardiologists use cardiac catheterization to assess the functioning of cardiac valves. Cardiac catheterization allows the identification of structural anomalies in the valves, and the evaluation of hemodynamic consequences of these anomalies, such as blood flow and oxygen levels in different parts of the heart. This helps cardiologists evaluate the risk and benefits of a surgical approach to treatment. In some cases, cardiac catheterization can also be used to measure hemodynamic values that may be needed prior to surgery in congenital heart disease, a condition caused by heart defect at birth. Cardiac catheterization is also indicated when percutaneous interventional approach (insertion of wires and catheters through the skin to treat cardiovascular problems) is selected to correct defects in congenital heart disease.
There is a normal supply of blood to the heart and no blockages.
What Abnormal Results Mean
An abnormal result may mean you have a blocked artery. The test can show how many coronary arteries are blocked, where they are blocked, and the severity of the blockages.
Cardiac catheterization carries a slightly increased risk when compared with other heart tests. However, the test is very safe when performed by an experienced team.
Generally, the risk for serious complications ranges from 1 in 1,000 to 1 in 500. Risks of the procedure include the following:
- Cardiac tamponade
- Irregular heartbeats
- Injury to a heart artery
- Low blood pressure
- Allergic reaction to contrast dye or a medicine administered during the exam
- Heart attack
Considerations associated with any type of catheterization include the following:
- In general, there is a risk for bleeding, infection, and pain at the IV or catheter site.
- There is always a very small risk that the soft plastic catheters could damage the blood vessels or surrounding structures.
- Blood clots could form on the catheters and later block blood vessels elsewhere in the body.
- The contrast dye could damage the kidneys (particularly in people with diabetes or prior kidney problems).
If a blockage is found, your provider may perform a percutaneous coronary intervention (PCI) to open the blockage. This can be done during the same procedure, but may be delayed for various reasons.
Dangas GD, Mehran R. Coronary angiography and intravascular imaging. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 21.
Fihn SD, Blankenship JC, Alexander KP, et al. 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update of the guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, and the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2014;64(18):1929-1949. PMID: 25077860
Kern MJ, Kirtane AJ. Catheterization and angiography. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 51.
Werns S. Acute coronary syndromes and acute myocardial infarction. In: Parrillo JE, Dellinger RP, eds. Critical Care Medicine: Principles of Diagnosis and Management in the Adult. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 29.
Last reviewed on: 1/1/2023
Reviewed by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.