Electrical signals from the heart can be measured from the surface of the skin by attaching electrodes from an ECG machine to the skin (see Figure 2.1). An ECG grid displays the time versus amplitude of electrical vector projections, which represent the conduction system of the heart.

Related Video – ECG and the Cardiac Cycle Basics

Figure 2.1. Electrocardiography

Electrocardiography

Figure 2.2 Electrocardiogram

Practitioner Reading an Electrocardiogram