Coronary Angiography

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What is Coronary Angiography?

A coronary angiogram is a procedure that looks at the coronary arteries in your heart to detect narrowing or blockages. The coronary arteries are the blood vessels that supply blood to the heart muscle. During a coronary angiogram, a small tube (catheter) is inserted through a large artery in the wrist or the groin, and is advanced to the heart and placed at the openings of the coronary arteries. To see the coronary arteries, a special contrast dye is injected through the catheter and into the blood vessels. Using live X-ray, pictures are taken to detect the location and severity of the blockages. This will help your doctor plan your treatment.

What causes narrowed coronary arteries?

Coronary artery disease develops when the arteries that supply blood to your heart become narrowed or blocked by a build-up of fatty cholesterol deposits called plaque. This process is known as atherosclerosis and develops over time.

Why do I need a Coronary Angiogram?

Your doctor may order a coronary angiography if you have the following:

  • Symptoms suggestive of coronary artery disease, such as chest pain or angina, shortness of breath, heaviness in the chest, pain radiating to your jaw or arm, nausea, heartburn, and heavy sweating.
  • Prior investigations suggestive of coronary artery disease
  • To check for worsening of pre-existing coronary artery disease
  • To check on the outcome of previous coronary treatment (angioplasty or bypass surgery)
  • To assess the condition prior to heart valve surgery or other major surgery


Is Coronary Angiography Safe?

Coronary angiography is a safe and well-tolerated procedure.

Less serious complications occur uncommonly (1-3%) and include:

  • Bleeding and bruising at the puncture site
  • Allergic reaction to contrast dye or medications
  • Local anaesthetic and sedation risks

Major complications are rare (<1%) and include:

  • Heart attack
  • Abnormal heart rhythm
  • Stroke
  • Kidney damage
  • Vessel injury
  • Emergency surgery
  • Death
How do I prepare for Coronary Angiography?

Your doctor will carefully review your medical history and do a physical examination. Routine tests before the procedure may include blood tests and an electrocardiogram (ECG).

To prepare for your procedure, please inform your doctor of the following:

  • The medications that you are currently taking as some medications need to be stopped before the procedure.
  • Any allergies or any medications you cannot take
  • Any bleeding problems you may have
  • Any surgery or dental work you may have soon
  • If you are pregnant or nursing, or have any plans to get pregnant

Your doctor will give you a set of specific instructions before the procedure:

  • Fast for at least 6 hours before the procedure
  • Please do not take your diabetic medications on the day of the procedure
  • On the day of the procedure, take only the approved medications with tiny sips of water. Ensure that all the other necessary medications have been packed to take to the hospital.
  • You will be instructed to come to the Cardiac Catheterisation Laboratory, a specialised X-ray facility located within the hospital
What happens during Coronary Angiography?

Right before Coronary Angiography

  • Remove all jewellery on your body.
  • An intravenous line will be placed for you.
  • You may be given a sedative either orally or through the intravenous line to help you relax.
  • You will be connected to an ECG monitor. Your vital signs (heart rate, blood pressure, breathing rate, and oxygen level) will also be monitored throughout
  • The puncture site (your wrist and/or groin) will be cleaned with an antiseptic solution and a sterile drape will be used to cover you

During Coronary Angiography:

  • A local anaesthetic will be given to numb the puncture site (wrist or groin).
  • Following vessel puncture with a needle and a small skin cut, a small tubing (sheath) will be inserted into the vessel.
  • A catheter will be passed through the sheath and into the arm vessel or the aorta to reach the heart.
  • Once the catheter is placed at the opening of the coronary arteries, contrast dye is injected to visualise the coronary arteries under X-ray.
  • As the procedure is done under live X-ray, X-ray machines will be rotating around you.
  • Upon completion of the procedure, the sheath will be removed from your wrist or groin, and firm constant pressure at the puncture site will be applied to avoid bleeding.
  • In some cases, a special vessel closure device may be placed.

The angiogram procedure takes about 30-45 minutes to complete. If necessary, further tests such as pressure and flow assessment and intracoronary imaging may be done during the coronary angiography. Angioplasty (ballooning and stenting) may also be performed in the same setting. The procedure will then be extended to 1-2 hours depending on the complexity.

You will remain awake during the procedure. The procedure should be painless except for mild discomfort at the puncture site. Please inform your doctor if you feel any discomfort at any time so that they can help you.

What happens if there is a serious narrowing detected during Coronary Angiography?

If a serious narrowing of the arteries is detected, a coronary Coronary Angioplasty/ Stenting is performed. This procedure, also known as a percutaneous coronary intervention Percutaneous Coronary Intervention (PCI) helps improve blood flow to the heart muscles by opening up the blocked artery.

Recovery after Coronary Angiography

After angiography, you will need to be observed and rest in bed for at least 4 hours. Your blood pressure, heart rate and puncture site will be monitored closely. During this time, you should:

  • Listen to the instructions of the nurses caring for you.
  • Do not bend your arm or leg (puncture area).
  • Report any swelling, pain, bleeding, or discomfort, especially around the puncture area.
  • Report any chest pain.

You will likely be discharged after observing for a few hours. You are encouraged to make prior arrangements for someone to bring you home, especially if you have been given sedatives. Some of your medications may be adjusted on discharge.

Going Home after Coronary Angiography

Before you go home, you will receive a set of specific instructions. Please follow these instructions to prevent any complications. When you reach home, please take note of the following:

  • Do not drive for the next 24 hours.
  • Monitor the puncture area for bleeding, bruising, or swelling. If bleeding occurs, lie flat and press firmly on the puncture site. If bleeding does not resolve, please seek medical attention.
  • Avoid any kind of strenuous exercise and do not lift heavy objects for at least 7 days.
  • Drink plenty of fluids to help the body flush out the contrast dye.
  • Take the medications prescribed for you.
  • Visit your doctor to check on your puncture site in 1 week.

How can we help you?

We offer consultation for a comprehensive range of cardiac diagnostic tests and treatment plans.

Dr Joshua Loh

Senior Consultant Interventional Cardiologist

Medical Director at Capital Heart Centre, Dr Joshua Loh has more than 15 years of experience in the field of cardiology.

He has extensive experience in the treatment of complex coronary and interventional procedures.