There are several different tests and investigations used to diagnose heart disease (mate manawa). These include an ECG (electrocardiogram), echocardiogram, and coronary angiography.
The tests your doctor chooses for you will depend on your risk of heart disease, your history of heart problems, and the symptoms you might have.
The ECG is the most common test for heart conditions. It is a simple, painless test that takes about 10 minutes.
Every time the heart beats, natural electrical currents can be picked up by electrodes placed on the chest, arms and legs. An electrocardiogram machine records your heart's rhythm onto paper. The recording will show whether the heart muscle is damaged or is short of oxygen.
Exercise ECG (treadmill test or stress test)
Some heart problems only appear when your heart needs to work harder. You may need an exercise ECG (a continuous ECG) to show how your heart is coping when you are exercising, instead of resting. While you walk on a treadmill, which will slowly get faster and tilt uphill, your heart rhythm and blood pressure will be recorded. The test takes about 10 minutes.
Holter monitoring (24 hour ECG)
The Holter monitor is used to identify any heart rhythm problems. The Holter monitor is a small, portable, battery powered ECG machine worn when at home over a 24 to 48-hour period.
It will record your heart rate and rhythm over this time and you will be asked to keep a diary of what you do and any symptoms that you experience while you are wearing the Holter monitor. At the end of the time period, the monitor needs to be returned to the hospital or clinic so the recorded information can be studied.
This test uses ultrasound (sound waves) to study the structure of your heart and how the heart and valves are working. A probe is passed over your chest and heart which sends out and records these sound waves, showing a moving image of your heart on a computer.
Echocardiogram stress test
A stress echo test is performed to see how your heart works while you exercise. An echocardiogram is taken while you rest, you then exercise, and then another echo is done while your heart is beating fast. Alternatively, if you are unable to exercise, you are given medication via an intravenous (IV) needle in your arm which makes your heart react as if your body was exercising.
Transoesphageal echocardiogram (TOE)
A TOE is a special type of echocardiogram. Pictures of your heart are taken by inserting a probe into your throat (oesophagus). These pictures are clearer because the oesophagus is close to your heart and there is no chest wall in the way.
A local anaesthetic solution is sprayed onto the back of the throat to numb the area. Although you will be awake during the procedure, you will be given some medication to make you feel relaxed and drowsy.
Your nurse will advise when you can eat and drink again; this is usually about two hours after the test. Occasionally people have a sore throat for 24 hours following the procedure.
Angiography (cardiac catheterisation)
Coronary angiography is an x-ray procedure used to examine the arteries of the heart. An introducing sheath is inserted into an artery, usually in your groin or arm.
A catheter is threaded through this to the part of the aorta near the heart, where the coronary arteries start. A special dye is injected through the catheter, into your bloodstream.
X-rays of the heart and coronary arteries are then taken. The dye highlights the coronary arteries and the narrowings in them. Your cardiologist will then review the x-rays and discuss the results with you. Read more...
Electrophysiological studies (EPS)
Your cardiologist might refer you for electrophysiology studies if you have an abnormal heart rhythm or palpitations.
Similar to an angiography, fine tubes called electrode catheters are introduced through a vein and/or artery, usually in the groin. They are then gently moved into position in the heart, where they stimulate the heart and record the heart's electrical activity.
Tilt table test
If you have episodes of fainting, a tilt table test is used to investigate if these could be related to your heart. For the test you lie on a special table, which can be angled to have you lying down or standing up. You will be attached to a heart and blood pressure monitor, which will record how your heart rate and blood pressure respond to changes in position. During the test you may have an intravenous (IV) needle inserted in your arm so you can be given medication.
A blood sample may be taken to help diagnose a condition or to help monitor someone who has already been diagnosed with a heart condition. Blood tests can also be taken to monitor the effects of medication as well as the levels of minerals in the blood.
Blood tests for cardiac troponin measurements can help either confirm or exclude a heart attack in a person who may be having, or recently had, a cardiac event. They can also help decide what treatments a person with unstable angina may need.
Troponin T and Troponin I are proteins that are part of the heart or cardiac muscle. When heart muscle injury occurs, these proteins are released. This makes them a valuable test to detect mild heart attacks. They can be detected in blood as early as three hours after a heart attack-associated chest pain starts. The levels peak at 10 to 24 hours and can still be detected up to five to 10 days later.
This means that if you have had chest pain for several days a heart attack can still be detected.