Cardiac investigations

Echocardiography

An echocardiogram is an ultrasound of the heart. It gives detailed information on the structure and function of the heart, including the movement of the valves, the heart muscle, and the flow of blood through the heart.

When you have an echocardiogram, you will be lying on a bed on your left side. The sonographer will apply a small ultrasound probe to the left side of the chest next to the breastbone, over the left ribs, at the bottom of the breastbone, and at the front of the neck.

The tech may ask you to breath in and out to improve the quality of the pictures. When you breathe, the heart moves in the chest and changes what is seen by the probe.

Transoesophageal Echocardiography

A transoesophageal echocardiogram, or TOE, is an ultrasound of the heart, but the pictures are obtained by inserting a small probe into the oesophagus.

The heart is close to the oesophagus, so the pictures can be clearer and more detailed then with a trans-thoracic echocardiogram, where the pictures are obtained through layers of chest wall, muscle and bone.

TOE is usually done when clear pictures are needed of the valves or other heart structures, such as to prepare for valve surgery

A TOE is performed under sedation, rarely we need to perform a general anaesthetic.

A TOE is a day procedure, you will be asked to fast and stay in the hospital for the day. You will need someone to pick you up and take you home afterwards.

Exercise stress testing

An exercise stress test requires an assessment of the heart before and after exercise. The exercise increases the heart rate and the amount of blood pumped with each beat. This can give us some good information about how the heart is responding under ordinary stress.

Exercise performed can include walking on an incline treadmill or cycling on a stationary bike.

An exercise stress test can involve cardiac assessment with ECG, echocardiogram, or a nuclear test (a stress MIBI scan).

One of the main aims of a stress test is to see whether the walls of the heart are moving normally under stress. When they are not, this can indicate a significant narrowing in one of the coronary blood vessels.

However, we also use this information to understand how the pressures are changing in the heart, how the valves are working, and how the body is coping with a cardiac lesion in the lead up to surgery or pregnancy.

Cardiac MRI

A cardiac MRI is a highly specialised scan that uses a magnetic field to create detailed images of your heart. It allows doctors to assess how well your heart muscle is working, evaluate blood flow, and identify areas of scarring, inflammation, or other changes.

At the Royal Melbourne Hospital we have particular expertise in cardiac MRI for:

• congenital heart disease
• valvular heart disease
• heart rhythm disorders
• cancer treatment affecting the heart (cardio-oncology)
• heart muscle diseases (cardiomyopathy)

During the scan you will be asked to lie still for 30 to 60 minutes and follow simple breathing instructions.

Coronary CT

A cardiac CT scan uses X-rays to produce detailed images of your heart and blood vessels. It is most commonly used to detect plaque build-up and narrowing in the coronary arteries, a test often called CT coronary angiography (CTCA).

At the Royal Melbourne Hospital we also have an interest in the use of cardiac CT for congenital, structural and valvular heart disease.

Before the scan you may be given medication to slow down your heart beat. This means you may be in the department for a couple of hours, although the scan itself only takes a few minutes.

During the scan, you will be asked to lie still and follow simple breathing instructions, and will usually receive a small injection of contrast dye.