An electrocardiogram (ECG) is a medical test that detects cardiac (heart) abnormalities by measuring the electrical activity generated by the heart as it contracts.
The machine that records the patient’s ECG is called an electrocardiograph. The electrocardiograph records the electrical activity of the heart muscle and displays this data as a trace on a screen or on paper.
This data is then interpreted by a medical practitioner. ECGs from normal, healthy hearts have a characteristic shape. Any irregularity in the heart rhythm or damage to the heart muscle can change the electrical activity of the heart so that the shape of the ECG is changed.
A doctor may recommend an ECG for patients ELECTROCARDIOGRAM who may be at risk of heart disease because there is a family history of heart disease, or because they smoke, are overweight, or have diabetes, high cholesterol or high blood pressure.
Some of the various heart problems that can be diagnosed by ECG include:
- Enlargement of the heart
- Congenital heart defects involving the conducting (electrical) system
- Abnormal rhythm (arrhythmia) – rapid, slow or irregular heart beats
- Damage to the heart such as when one of the heart’s arteries is blocked (coronary occlusion)
- Poor blood supply to the heart
- Abnormal position of the heart
- Heart inflammation – pericarditis or myocarditis
- Cardiac arrest during emergency room or intensive care monitoring
- Disturbances of the heart’s conducting system
- Imbalances in the blood chemicals (electrolytes) that control heart activity.
A person with heart disease may have a normal ECG result if the condition does not cause a disturbance in the electrical activity of the heart. Other diagnostic methods may be recommended if heart disease is suspected.