8 Common Heart Scans and Tests

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

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 differently and forms shadows and outlines of the heart, lung and bones.

Chest x-rays are also 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
• You experience chest pain, shortness of breath or a persistent cough

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. Our staff will give you a hospital gown to wear and you may need to remove jewellery, eye 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 (a doctor who specialises in interpretation of x-rays) will review your images before sharing the results with you.

Blood test

Blood tests are performed for many reasons. In emergencies, it can measure substances in the blood that show up and how much damage the heart muscle has suffered. When heart muscle is damaged from a heart attack, the damaged muscle releases substances into the blood stream that can be measured in a blood test.

Blood tests are also performed to diagnose diabetes and high cholesterol; and to monitor the kidney and liver function to help decide what medications are needed or can't be given in someone with a heart condition.

12-lead electrocardiogram (ECG)

A 12-lead ECG is a 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 (or "leads") to represent 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).

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 a person's heart works under stress. As exercise makes the heart pump harder and faster, it can help to reveal problems with the blood flow within the heart, blood pressure fluctuations and heart rhythm problems. 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 both still and 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 and if there is scarring within the heart.

Echocardiogram

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.

Patients with chest pain and breathlessness may require an echocardiogram to diagnose fluid-buildup, heart valve problems or other conditions such as blood clots in the lung. This will enable the doctor to determine the cause and effect of the condition and optimise 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, heart rhythm disorders or a heart attack
• Your newborn baby has a suspected heart defect

There are several different types of echocardiogram, including:

• Transthoracic – The ultrasound probe is placed on your chest to obtain images
• Fetal – The doctor places the ultrasound device on your belly to check for heart problems in the foetus
• Transoesophageal – The doctor inserts the 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 and after the test. You might also have a slight sore throat after this procedure.

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

CT scan of the heart

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 a special type of CT scan that can look for problems with the heart.

A Coronary Calcium Scan, is 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). A Coronary Calcium Scan is quick and easy to perform and you won't need to make any special preparations. It checks for 'hardened' build-up of calcium and cholesterol that can crack and create a blood clot which can cause a heart attack. 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 volume of calcium deposits. The scores are interpreted as follows and is dependent on the age of the patient. But in general, 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 heart arteries. Your doctor will inject a dye into your arteries via a vein in your hand or arm, and this will outline the heart arteries and any blockages if present.

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

The staff 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.