Uses of an ECG

An electrocardiogram (ECG) is a tracing, or drawing, produced by an electrocardiograph – a device which records electrical activity in the heart. An ECG can be used for:

§ deciding if the heart is performing normally or suffering from abnormalities, for example cardiac arrhythmia – extra or skipped heartbeats

§ indicating damage to heart muscle, such as heart attacks, or ischaemia of heart muscle (angina)

§ detecting conduction abnormalities: heart blocks and bundle branch blocks (BBB)

§ screening for ischaemic heart disease during an exercise tolerance test, often carried out on an exercise bike or treadmill

§ providing information on the physical condition of the heart, for example in patients with left ventricular hypertrophy (LVH)

§ detecting electrolyte disturbances, for example low plasma potassium levels.

ECG procedure

Here is an extract from a medical textbook.