28.MAY.2018 6 MIN READ | 6 MIN READ

On average, your heart beats 115,200 times a day, or 42,048,000 times a year. You should take care of this incredible muscle!

Last updated on 19 October 2020

Ventricles, valves, veins and arteries – the heart is a complicated system that pumps blood around the body, provides it with the oxygen and nutrients it needs, and gets rid of waste.

But such a complicated system can go wrong. Unfortunately, you might not always be aware of this happening, as not all heart conditions cause symptoms.

If you’re concerned about your heart health, don’t be afraid to speak to a specialist.

Here are some ways your doctor can scope out your heart!

Chest x-ray

Chest x-ray
An x-ray is a common medical scan that produces images of your organs, tissues and bones. X-rays are high-energy photons (light, on the other hand, is made up of low-energy photons) that are partially absorbed by your body’s bones and soft tissues, and forms shadows and outlines of the heart, lung and bones.

Besides your heart, chest x-rays can also be used to check for other serious conditions such as pneumonia, emphysema and lung cancer. Your doctor may recommend one if:

  • You’ve had an accident or chest injury
  • You experience chest pain, shortness of breath or a persistent cough

While the process may sound a bit scary, x-rays are actually quick and easy tests that only expose your body to a small amount of radiation. You won’t need to do anything special to prepare. Your doctor will give you a hospital gown to wear and you’ll need to remove any jewellery, glasses or body piercings. Make sure to let your doctor know if you have a metal implant, like a pacemaker, and very importantly, if you’re pregnant or likely to be pregnant.

Your doctor and radiologist (x-ray specialist) will both review your images before sharing the results with you.

Blood test

Blood tests are performed to measure substances in the blood that show if and how much the heart muscle has been damaged. For example, when the heart muscle is damaged from a heart attack, the body releases substances into the blood that are then measured. Blood tests are also done to measure the level of various substances in the blood such as cholesterol, triglycerides, vitamins and minerals or monitor the effects of medications. They can help to diagnose a condition or monitor someone who has already been diagnosed with heart condition. A blood sample is drawn from a vein in the arm for this purpose.

12-lead electrocardiogram (ECG)

A 12-lead ECG is another quick and painless test. It is used to assess the electrical circuit of the heart. Thickened heart muscles, heart attacks, and irregular heart rhythms will show up as changes on an ECG. Your doctor will attach 10 electrodes to your chest, arms and legs to produce 12 different views of your heart’s electronic activity. This is usually first done ‘at rest’ (so you’ll be lying down), but your doctor may also want to check how your heart copes with stress (induced by treadmill exercise or medication).

12-lead ECG
Your doctor may recommend a 12-lead ECG if:

  • You may have or have high blood pressure
  • You’re experiencing chest pain, shortness of breath or palpitations
  • You’re at risk of heart disease (eg. if you have a family history of the condition, or if you have diabetes)
  • You have had a fainting episode

Like x-rays, you won’t need to do much to prepare for a 12-lead ECG. Just avoid applying greasy creams or lotions to your skin on the day of the test so your doctor can easily attach the electrodes. Sometimes, the doctor may also need to shave a part of the chest to enable the electrodes to stick properly. The entire test shouldn’t take more than 10 minutes. Your doctor will then review the ECG for any unusual electrical activity in your heart rhythm.

Exercise stress test

A stress test, sometimes called an ‘exercise’ test, is a type of ECG that is done while a person is exercising. The purpose of this test is to determine how well the person’s heart works when physically active. As exercise makes the heart pump harder and faster, an exercise stress test can reveal problems with blood flow within the heart. The stress test usually involves walking on a treadmill or riding a stationary bike, during which the heart rhythm, blood pressure, and breathing are monitored.

Magnetic resonance imaging (MRI)

An MRI is done to create detailed images of the heart on a computer using very strong magnets and radio waves. It takes still or moving pictures of the heart. A special dye is sometimes used to make parts of the heart and coronary arteries more visible. The MRI can show the doctor the structure of the heart and how well it is functioning.


An echocardiogram uses high-frequency sound waves (ultrasound) to produce images of your heart. This enables the doctor to assess the heart’s function and structure. Chest pain, breathlessness, fluid-buildup, or other conditions causing blood clots in the lung may require an echocardiogram. This will enable the doctor to determine the cause and consequence of the condition and tailor a treatment for you. It is routinely performed after a heart attack.

Your doctor may recommend an echocardiogram if:

  • You are suspected to suffer from heart disease such as heart failure, heart valve dysfunction or a heart attack
  • Your newborn baby has a suspected heart defect

There are several different types of echocardiogram, including:

  • Trans-thoracic – The doctor places the ultrasound device on your chest
  • Fetal – The doctor places the ultrasound device on your belly to check for heart problems in the fetus
  • Trans-oesophageal – The doctor inserts an ultrasound device into your throat and down your gullet. This requires sedation and cardiac monitoring
  • 3D echocardiogram – Some trans-thoracic and trans-oesophageal machines can create 3D images of your heart. This is useful before heart valve surgery, or to assess heart defects in babies
  • Stress echocardiogram – It is similar to the trans-thoracic echocardiogram, except that in addition, the doctor will repeat the scan after the heart has been adequately stressed (induced by treadmill exercise or medication). This is more sensitive and precise than a normal ECG treadmill, and has a unique ability to pick out additional problems such as heart valve dysfunction during stress

Unlike x-rays, echocardiograms don’t use radiation. They are generally considered very safe. You won’t need to do anything special to prepare, unless you’re having a trans-oesophageal echocardiogram, in which case you may need to avoid eating for a few hours before the test. You might also have a slight sore throat after this procedure.

Your doctor will check the results and recommend appropriate treatment if they find evidence of heart damage, heart defects or valve problems.

CT scan of the heart

CT scan
A computer tomography (CT) scan of the heart uses information from multiple x-rays obtained rapidly to produce a 3D image of the heart. Coronary CT angiograms are just one type of CT scan to check for problems with the heart. Others include:

  • A coronary calcium scan, a plain CT scan of the heart without the use of contrast (a liquid used in CT scans to increase the visibility of internal tissues in the body).

It’s quick and easy for your doctor to perform and you won’t need to make any special preparations. It checks for ‘hardened’ plaques (build-up of calcium and cholesterol) that can crack and create a blood clot blocking the artery. If you’re at risk of a heart attack, this test will go some way towards evaluating that risk. Based on the results, your doctor might recommend a more detailed test, or suggest changes to your lifestyle (eg. medication, diet and exercise).

  • CT scans are also used to assess other parts of the body, but as each organ requires a slightly different scan protocol, and because of the radiation involved, your doctor will order a CT scan depending on your needs.

Coronary calcium scan results

The results of the coronary calcium scan are usually given as a number called an Agatston score, which reflects the total area of calcium deposits and the density of the calcium. The scores are interpreted as follows:

  • 0: No calcium is seen in the heart, suggesting a low chance of developing a heart attack in the future
  • 100 – 300: Moderate plaque deposits are present. It is associated with a relatively high risk of heart attack or other heart disease over the next 3 – 5 years.
  • > 300: Indicates very high to severe disease and heart attack risk

Coronary CT angiogram

A coronary CT angiogram is a special x-ray test that checks for blockages in the passageways to your heart. Your doctor will inject a dye into your arteries via a vein in your hand or arm, and this will outline the blockages on the images generated.

Your doctor may recommend a coronary CT angiogram if you have:

  • Unexplained chest pain or discomfort
  • Unusually high blood pressure and/or symptoms that suggests you have a tear in your major artery
  • Highly abnormal CT coronary calcium score
  • Borderline results from your stress test

Coronary CT angiogram
Your doctor will also place electrodes on your chest to monitor your heart’s electrical activity. You’ll need to stay still and hold your breath while the x-rays are being taken, which will only take 1 – 2 seconds. There will also be a few smaller preliminary scans to help the radiographer plan the final scan.

Usually, your doctor will recommend avoiding eating and drinking for at least 4 hours before the test, in case you have an allergic reaction to the contrast. After the test, you’ll be able to resume your normal activities, but will be asked to drink water to clean out the contrast inside your body. Always inform the doctor or radiographer if you’re pregnant or likely to be pregnant.

If your doctor discovers a blockage, they will discuss treatment options. These include another test to determine the significance of the blockage, a coronary angiogram, or an intensive medical management to reduce your blood cholesterol and other risk factors.

If you’d like to arrange for a heart scan, make an appointment with a specialist.


Article reviewed by Dr Ong Hean Yee, cardiologist at Mount Elizabeth Novena Hospital


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Ong Hean Yee
Mount Elizabeth Hospital

Dr Ong Hean Yee is a cardiologist practising at Mount Elizabeth Novena Hospital, Singapore. He has special clinical and research interests in the areas of cardiac screening, lipidaemia, exercise testing, heart failure and advanced cardiac imaging.