How a pacemaker works

A pacemaker has two different functions. Firstly, it continuously observes the heart rhythm in order to detect abnormal rhythms (sensing). When heartbeats are too slow, the pacemaker stimulates the heart muscle by sending electrical signals which correct the slow heart rhythm (pacing). In other words, the pacemaker “senses” the heart rhythm continuously, but “paces” the heart only when needed.

Pacemakers have additional functions in order to optimize the heart rhythm. One of these functions is the sensor function (so called rate response). A sensor detects physical activity (either via the body motion, the breathing rate or cardiac contractility) and based on that the pacemaker increases the heart rate when needed (e.g. during exercise).

A pacemaker consists of two parts:

• The pulse generator: a small metal case which contains the battery of the pacemaker and the electrical circuit which senses the heart beats and produces the electrical signals.
• The leads: thin insulated wires connected with the pulse generator at one end and a chamber of the heart on the other end. The leads are implanted via a vein in the chest below the clavicle and advanced to the heart. The electrodes deliver the electrical signals to the chamber that the pacemaker “paces”, controlling the rate of the heart rhythm. They also “sense” the electric activity of the heart, sending this information back to the pulse generator.

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FREQUENTLY ASKED QUESTIONS

How does a pacemaker work?

A pacemaker sends electrical impulses to the heart to stimulate a normal heart rate and rhythm when the heart’s natural pacemaker fails.

What does a pacemaker do?

It monitors heart rhythms and provides electrical stimulation as needed to maintain a consistent and adequate heartbeat.

Does a pacemaker work continuously?

Pacemakers monitor heart rhythms, and provide electrical stimulation only when they detect an abnormal rhythm, providing support as needed.

Can a pacemaker adjust to physical activity?

Yes, modern pacemakers have sensors that detect physical activity and adjust the heart rate accordingly.

What components make up a pacemaker?

A pacemaker consists of a generator, which produces electrical impulses, and leads that deliver them to the heart.

How is a pacemaker powered?

Pacemakers are powered by long-lasting batteries that typically last 5-15 years.

Can a pacemaker prevent all heart rhythm problems?

A pacemaker manages slow rhythms but does not treat fast arrhythmias or other heart conditions.