What is an ECG?
ECG stands for electrocardiogram.
During an ECG, small electrodes are placed on the chest, arms and legs. These electrodes record the electrical signals that control the heart. The signals are then displayed as a graph, which can be assessed by a doctor or cardiologist.
Because the heart continuously produces electrical impulses to contract and pump blood around the body, an ECG can provide valuable information about how the heart functions.
How does an ECG work?
The heart functions through electrical impulses that cause the heart muscle to contract.
These electrical signals originate in the sinus node, a group of specialised cells in the heart that controls the heart rhythm. The signals then spread through the heart muscle, allowing the heart to pump blood in a coordinated rhythm.
During an ECG, electrodes placed on the skin record this electrical activity. The examination therefore does not show what the heart looks like, but rather how it functions electrically.
A standard ECG usually takes just a few minutes.
What can an ECG detect?
An ECG can provide information about various aspects of heart function.
For example, an ECG may reveal signs of:
- Heart rhythm disorders (arrhythmias)
- An unusually fast or slow heart rate
- Abnormalities in the heart's electrical conduction system
- Possible damage to the heart muscle
- Signs of reduced blood flow to the heart
An ECG is therefore an important tool in assessing cardiovascular health.
Want to learn more about how the heart works? Read our knowledge base article about the heart.
What can an ECG not detect?
Although an ECG provides valuable information about the heart's electrical activity, it also has limitations.
For example, an ECG cannot show how the heart valves function or how effectively the heart pumps blood. In addition, some heart problems may not be detected if they are not present at the time of the examination.
For this reason, an ECG is sometimes combined with other examinations, such as an echocardiogram or an exercise stress test.
What happens during an ECG examination?
An ECG is a simple and painless examination.
During the examination, electrodes are placed on the chest and limbs. The ECG machine then records the heart's electrical activity for a few minutes.
The examination does not involve needles, injections or other invasive procedures. Afterwards, the results can be assessed by a doctor or cardiologist.
Is an ECG safe?
An ECG is considered a very safe examination.
The machine only records the heart's electrical activity and does not send any electrical current into the body. As a result, there are no known health risks associated with a standard ECG.
Occasionally, mild skin irritation may occur where the electrodes were attached, but this is usually temporary.
When is an ECG used in preventive healthcare?
An ECG can be part of a preventive cardiac examination.
The aim is to gain more insight into how the heart functions and to identify potential abnormalities in heart rhythm or electrical conduction at an early stage.
A preventive examination is intended for people without known heart-related symptoms. If someone is currently experiencing heart-related symptoms or has recently been under the care of a cardiologist, a preventive health check may not be appropriate. In such cases, seeking regular medical care through a GP or treating specialist is the recommended approach.
Want to learn more about conditions affecting the heart and blood vessels? Read our article about cardiovascular diseases.
Conclusion
An ECG, also known as an electrocardiogram, measures the electrical activity of the heart. The examination provides insight into heart rhythm, heart rate and the electrical conduction system of the heart.
Because an ECG is quick, safe and non-invasive, it is widely used in cardiology and preventive healthcare. Although it cannot assess every aspect of heart function, it is a valuable tool for gaining a better understanding of how the heart works
