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Home > Our Services > Conditions and Treatments > Coronary Angiography

Coronary Angiography






Coronary Angiography is a procedure to visualize the coronary arteries. The coronary arteries are the blood vessels that supply blood to the heart muscles. On ordinary chest X-ray films, the heart appears as a silhouette and the coronary arteries cannot be seen. To see the coronary arteries, a special dye or contrast medium is injected through a small tube (catheter) inserted into a large artery in the groin or the wrist. The catheter is then advanced to the heart and positioned at the mouths of the coronary arteries before injection is performed.


Coronary angiography is therefore an invasive procedure. Sometimes, another procedure called a left ventriculography is performed at the same session, whereby a catheter is advanced into the left ventricle (the lower and larger heart chamber) and contrast medium injected. This allows visualization of the left ventricle and its contractions.



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What is the purpose of this test?


In some people, the coronary arteries become narrowed, usually by a process called atherosclerosis in which cholesterol and other substances are deposited in the arterial wall. With progressive narrowing, the blood supply to the heart muscle gradually decreases, and eventually becomes insufficient to supply its needs. This usually results in chest pain (angina pectoris) during exertion or stress, but may also manifest as breathlessness, irregular heart rhythm or fatigue. When a blood vessel suddenly occludes completely, afull-blown heart attack occurs. Coronary artery disease is a common disease and a major killer in Singapore.


Coronary Angiography is carried out to determine whether there is any significant narrowing or blockage in the coronary arteries. Once determined, the doctor will decide on the best form of treatment to carry out.


It is also performed before Coronary Angioplasty (ballooning) is carried out to provide a 'road map' for guiding the Angioplasty procedure.





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What to expect?


The procedure may be performed on an outpatient basis, or you may be admitted overnight.


Before the procedure:

  • Routine investigations, including blood tests, and Electrocardiogram (ECG) and a chest X-ray may be carried out
  • You would not be allowed food nor water for 6-8 hours before the procedure
  • A small cannula will be inserted in one of the veins on your hand/arm to facilitate injection of medicine, if necessary
  • You would be asked to sign a consent form after your doctor has explained the risks of the procedure to you


On the day of the procedure:

  • On the morning of the test, you will be asked to empty your bladder, and skin shaving usually on your groins and upper thighs will be done
  • You will be brought to the Invasive Cardiac Laboratory where you will be placed on a movable table, with X-ray cameras and LCD monitors around you
  • Do not be alarmed by the sound of the machines and you should try to relax and keep still.
  • A nurse will clean your groin or wrist, and then drape you with sterile towels.
  • The cardiologist performing the procedure will first apply local anaesthetic on either area by the doctor will be applied before the catheter is inserted into your body.
  • The procedure is painless, except for the initial injection of local anaesthetic.
  • If left ventriculography is performed, you will feel a warm sensation in your chest which then moves down to your legs during the injection of the contrast medium for a few seconds.


After the procedure:

  • The procedure normally takes 15-30 minutes, following which the catheters will be removed.
  • Upon removal, the doctor will discuss his findings with you.
  • and your puncture site will be compressed for about 10 to 15 minutes until the bleeding stops and the compressive bandage will be applied.
  • You would be brought back to your hospital bed where you would have to lie flat on your back for 4-6 hours until the doctor verifies that you are fit to walk.
  • Your doctor will then discuss the findings of the angiography, as well as treatment options.
  • You can be discharged on evening the same day's evening or early next day.


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What to prepare?


  • Please inform your doctor of any allergy, in particular, allergies to seafood, iodine, X-ray contrast medium and pain relieving medications.
  • Please inform your doctor if you have a history of peptic ulcer disease, recent strokes, or blooding tendencies.
  • If you are suffering from diabetes mellitus and you are taking a medication called metformin, please inform your doctor and you would need to stop this particular medication for at least 2 days before and after the Angiography.
  • Bring along some light reading material or a mini radio for your hospital stay as you will be spending much of your time in bed.
  • Please bring all your medications with you. You will be instructed which medication you will need to omit before the test.


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What are the potential risks or complications?


Coronary Angiography is one of the safest invasive procedures. There is small risk of injury and complications with regards to this procedure. Most complications are minor - bleeding, swelling and bruising from the puncture site and allergic reaction from the contrast medium. There is a very small risk (0.1%) of heart attack and stroke occurring during the procedure, and an even smaller risk (less than 0.1%) of major life-threatening complication. 


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Home care

As a patient:

  • Resume normal daily activities
  • Notify the doctor at once if you experience bleeding or increase bruising at the puncture site; or when you experience a recurrence of symptoms, such as breathlessness or decreased exercise tolerance.



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