An electrocardiogram, or ECG, records the electrical activity of your heart.
Small sticky patches called ‘electrodes’ are put on your chest, and sometimes your arms and legs. These are connected, by wires, to an ECG recording machine. The recording machine picks up the electrical activity in your heart and interprets it into graphs which are printed onto paper.
The whole test takes about five minutes.
An ECG can detect problems called arrhythmias. These are abnormal heart rhythms where the heart beats too slowly, too fast or irregularly. Or, if you get sudden symptoms such as chest pain, an ECG can help doctors to diagnose if you are having a heart attack.
An ECG can often show if a person has had a heart attack days, weeks or even years ago. It can also show if your heart might be enlarged, or if the heart wall might have become thicker because there has been too much strain on it.
The ECG is a simple and useful test, but it has some limitations. An abnormal reading does not necessarily mean that there’s something wrong with your heart.
Some people may have a normal ECG recording even though they do have a known heart condition. This is why you may need to have one or more other tests as well as the ECG.
Exercise ECG (ETT)
This test is also known as an exercise stress test or an exercise tolerance test.
An exercise ECG is an electrocardiogram (ECG) that is recorded while you are walking on a treadmill or cycling on an exercise bike. The idea of this test is to see how your heart works whilst you are moving about or exercising when your heart has to work harder. The heart needs more blood and oxygen when you are active. An exercise ECG can show if your heart muscle is receiving enough blood.
Several small sticky patches (electrodes) are put on your chest. These are connected, by wires, to an ECG machine to record all the electrical activity of your heart, in the same way as for the ECG described above. You will then be asked to exercise, either by walking on a treadmill or cycling on an exercise bike. The test starts off at a very easy rate and is gradually made harder. Your ECG reading, blood pressure and pulse will be monitored throughout the test. The test will be stopped when certain targets have been reached. The test would also be stopped if you started to get symptoms such as chest pain, chest tightness, shortness of breath, tiredness, blood pressure that is too high or too low, or an abnormal heart rhythm. Or if you felt you could not carry on with the test.
You will then be monitored for a period of recovery following the test.
The exercise test usually lasts between approximately 2 minutes and 15 minutes. It can be hard work, but should not be too much for you. Like many people, you may be pleasantly surprised by how much you can achieve. The value of the test is much greater if you try to work as hard as you can.
The test can help doctors find out if you have coronary heart disease. If, during the test, there are certain changes in the ECG pattern, or if you develop symptoms such as chest pain or chest tightness, or if there are abnormal changes in your blood pressure or heart rate, this may mean that there is narrowing of the coronary arteries and that you may need further tests.
If you already know you have coronary heart disease, an exercise ECG gives information about how severe your condition might be. For example, it can give some idea of how much strain your narrowed coronary arteries are under when you exercise. This can help your doctors to assess if your condition has got worse, and help them plan the best treatment for you.
An exercise ECG also helps doctors to see how well your heart is working if you have recently had heart surgery, coronary angioplasty / Stent, or a heart attack and can help doctors decide what level of exercise you should do as part of a cardiac rehabilitation programme.
This test can also be used if you have been collapsing or having blackouts, particularly if this happens while you are being active or exercising.
If you have coronary heart disease, an exercise ECG can show ‘ischaemic changes’ during exercise. This means that the test is showing that there is a reduced supply of oxygen to the heart muscle. If you get chest pain and there are ischaemic changes on the ECG recording at the same time, this could mean that the chest pain is coming from your heart.
The exercise ECG test may show changes that suggest coronary heart disease, even though the person has very few or no symptoms.
An exercise ECG is a very useful test. It is widely available and it’s a very safe test compared to many other medical tests. Most people find that the test is not unpleasant or distressing.
Cardio pulmonary Exercise Testing (CPET or CPEx)
Cardiopulmonary exercise testing is now the “gold standard” objective tool for evaluating cardiopulmonary function and fitness. CPEx testing is a non-invasive simultaneous measurement of the cardiovascular and respiratory system during exercise to assess your exercise capacity.
It is similar to the Exercise ECG but your breathing is also monitored while you walk on the treadmill or cycle on the bike we measure how much air you breathe, how much oxygen you need and how fast and efficiently your heart beats while you exercise.
This is the most common of the Lung function tests which look at how well your lungs work. It can help to diagnose various lung conditions, most commonly Chronic Obstructive Pulmonary Disease (COPD) but can also be used to monitor the severity of other lung conditions and their response to treatment e.g. Asthma, Pulmonary Fibrosis and Cystic Fibrosis
24-hour ECG recording
This test is also known as Holter monitoring or ambulatory ECG monitoring.
The test involves continuously recording your electrocardiogram (ECG), usually for 24 to 48 hours although it can be recorded for up to 7 days.
The test is safe and painless. It can help to diagnose the cause of symptoms such as palpitations which don’t happen all the time and which rarely happen in the GP’s surgery.
The recording device is a small digital device connected to 3 ECG recording leads which are taped to your chest. The device records the electrical activity of your heart. While you are wearing it, you can do everything you would normally do, except have a bath or shower.
You may be asked to keep a ‘diary’ while you’re wearing the device, and make a note of any times when you have symptoms. This can help when your results are analysed.
After the monitor is removed, the data is analysed and a report sent to your doctor who can then discuss the results with you and any further necessary treatment.
A 24-hour ECG recording can give a lot of useful information. It may show an abnormally fast, slow or irregular heart rhythm that may need treatment. Or, if you are having palpitations but the device records a normal heart rhythm, this can be reassuring for you. In most cases, palpitations are not due to any heart abnormality.
Cardiac Event Recorders
This is a very useful test for diagnosing symptoms that happen infrequently For example If you suffer with palpitations but they do not happen very often, or if you collapse occasionally but not regularly, your doctor may suggest using a cardiac event recorder to record your heart’s rate and rhythm over a longer period of time. You will be given a small electrical recording device to keep with you for several days or weeks. The advantage of this device is that there are no leads attached to it. When you experience your typical symptoms, you just need to hold it to your chest and activate it, and it will record your heart rhythm. You will be shown how to do this. It is not invasive or painful. The information will then be analysed and a report sent to your doctor who will discuss the results with you.
24-Hour Blood Pressure Recording
This test is also known as ambulatory blood pressure monitoring.
Your doctor may want to record your blood pressure at regular intervals over a 24-hour period. This can be done by using a special recording device.
A small portable recording device is worn on a belt around your waist for 24 hours. This is attached, via a tube under your clothes to a cuff which is wrapped around your arm. You can carry on with your usual daily activities except for having baths or showers.
Throughout a 24-hour period, including through the night, every hour or so, the cuff automatically inflates and measures your blood pressure. The recorder keeps a record of each blood pressure measurement and the time that it was taken.
The next day, when you go return to Heartbeat, the device is taken off and the data will be analysed. The results will be sent to your GP.
This test can give an overview of all the blood pressure readings throughout the 24 hours. It confirms whether you have high blood pressure or not. It is particularly useful if your doctor thinks that your blood pressure is unusually high when you have it measured in the doctor’s surgery or at hospital appointments. If you are already taking tablets for high blood pressure, it can tell how well or how poorly your blood pressure is controlled.
Most of the tests listed above are offered as part of the exercise programme provided by Heartbeat but they can also be done on a private basis.