Tests and scans

You'll be given a thorough physical examination and possibly one or more of the following heart investigations may be carried out.

Electrocardiogram (ECG)
This shows electrical activity in the heart. It can reveal the thickness of the heart muscle (this may indicate long-term strain due to high blood pressure), areas of damage after a heart attack, and whether the blood supply to the heart muscle is adequate.

Chest x-ray
This shows abnormalities in the size or shape of the heart, and whether fluid is building up in the lungs because the heart isn’t working efficiently as a pump.

Blood tests
These can pick up abnormalities that influence how well the heart is working. For example, they can detect raised levels of cholesterol (which may lead to coronary artery disease), abnormal levels of thyroid hormones (which can affect the heart’s strength and rhythm) and the presence of cardiac enzymes (chemicals released when heart muscle cells are damaged in a heart attack).

Exercise stress test (or treadmill test)
This monitors the heart during exercise and shows how well it responds when the demands on it are increased. It’s a good way to detect blockages in the blood flow through the coronary arteries to the muscle of the heart (coronary artery disease).

Thallium scan
Radioactive dye is injected during exercise to demonstrate the amount of blood reaching different parts of the heart's muscular walls.

Echocardiogram
This scan uses sound waves to create an image of the heart as it beats. It shows the structure of the heart, how the walls of the heart move, and how well the heart valves are working.

CT (or CAT - computerised axial tomography) and MRI (magnetic resonance imaging) scans
These sophisticated scans show a detailed image of the structure of the heart and how well it works.

Coronary angiography
This is a more complex test. Under the guidance of an x-ray camera, a long, thin tube is threaded into the coronary arteries via a blood vessel in the groin or arm. A dye, which can be seen on the x-ray screen, is then injected, showing the pattern of the coronary arteries, and demonstrating where the artery is narrowed. Sometimes treatment for the narrowed areas is given during the test, for example by inserting a tiny tube, known as a stent, which holds the walls of the artery open.

When the results of these and other tests are available, it's possible to build a picture of what is going wrong with the heart, reach a diagnosis and consider appropriate treatment.

Published March 2007