Heart Electricity

Electrocardiograms

Electrical waves (coloured yellow) pass through the heart to trigger contraction of the muscular walls. The heart needs coordinated electrical waves and smooth contraction to pump effectively.

The electrical waves in the heart can be measured by placing electrodes on the chest. This is called an electrocardiogram (ECG) recording, as shown on the right.

Click on fibrillation below to see what happens when this smooth electrical activity is disrupted.