An electrocardiogram (ECG) is a recording of the changes in electrical potentials in the heart, meaning heart activity. Sensors fastened to the ribcage, arms and legs of the patient detect electrical impulses that the heart gives off when contracting. An ECG is usually done within a few minutes with the patient in a resting position and is not in any way painful or uncomfortable.
The changes in electrical potentials give information about the heart rhythm and reveal possible dysfunctions in the activation process. An ECG can give information on the following illness and abnormalities:
- Heart attack
- Arrhythmias
- Inflammatory changes, for example to the heart muscle
- Enlargement of the heart
- Circulation problems in the coronary vessels
- (Side) effects of certain medications
- Changes to minerals in the blood
The ECG is one of the most basic heart examinations and often the first step in an initial examination.