A pacemaker is a medical device that helps regulate the heart's rhythm. It is typically used for patients who have arrhythmias, conditions where the heart beats too slowly (bradycardia) or erratically. The pacemaker consists of two main components: a pulse generator, which contains the battery and the electronic circuitry, and one or more leads that deliver electrical impulses to the heart.

When the heart's natural pacemaker (the sinoatrial node) fails to function properly, the pacemaker sends electrical signals to prompt the heart to beat at a normal rate. The device can be programmed to respond to the heart's needs, adjusting the pacing rate based on the body's activity levels.

Pacemakers can be temporary or permanent, depending on the underlying condition. After implantation, patients typically need regular follow-up appointments to monitor the pacemaker’s function and battery life. Modern pacemakers are small, reliable, and often equipped with advanced features like wireless monitoring capabilities, improving patient outcomes and quality of life.