The pacemaker is a small metal box that weighs 20–50g. It is attached to one or more pacing leads that lead to your heart.

The pacemaker contains:

• a battery, which lasts about 8 to 10 years.
• a pulse generator.
• a tiny computer circuit that converts the energy from the battery into electrical impulses that flow through the wires and cause your heart to contract.

The rate at which the electrical impulses are created is called the discharge rate.

Pacemakers work on demand, so they can be programmed to alter the discharge rate in response to your body’s needs. If the pacemaker identifies that your heart has missed a beat or is beating slowly, it fires signals at a steady rate. If it senses your heart beating normally, it will not send out any more signals.

Our pacemakers have a special sensor that senses your body movement and your breathing rate. This lets them to speed up the rate at which they work when you are active. These pacemakers are rate responsive.