When a pacemaker is essential

A pacemaker, a device that stimulates and maintains the heartbeat, becomes indispensable when the heart can no longer maintain a rhythm slow and regular enough to ensure proper blood circulation. In practice, it is used primarily in cases of pathological bradycardia (a heart rate that is too slow) or blockages in the heart's electrical system.

But a pacemaker is not inserted just because the heartbeat is a little slow, it becomes necessary when the slow rhythm causes symptoms or there is an electrical disturbance that risks worsening or stopping.

How a lifesaving device works

The heart isn't just a mechanical pump; it relies on an electrical system that regulates each beat. If that system fails, blood doesn't circulate properly. In some forms of heart block (especially complete AV block), electrical impulses no longer reach the ventricles. Without a pacemaker, the heart can progressively slow down, pause for prolonged periods, or even suffer cardiac arrest.

The pacemaker avoids all this by maintaining a minimum effective rhythm.

Furthermore, if the heart beats too slowly, the brain receives less oxygen and sudden fainting (syncope) may occur.

These episodes are not just annoying: they can be fatal if they occur while driving, at heights, or in other risky situations.

In some diseases (such as sick sinus syndrome), the heart alternates between beating too slowly and suddenly pausing. A pacemaker prevents these sudden drops in rhythm. It also prevents complications , as a too-slow rhythm can lead to heart failure (poor pumping), worsening blood pressure, and organ damage due to poor perfusion.

Types of pacemakers

Pacemakers can be classified in different ways: by the number of chambers stimulated , by function , and by implantation technology . Here are the main types.

• Single-chamber pacemaker

It stimulates only one chamber , usually the right ventricle, has a single lead, and is used when only a minimal heartbeat is needed. Simpler, but less "physiological," it can be useful, for example, in elderly people with atrial fibrillation.

• Dual-chamber pacemaker

It stimulates the right atrium and ventricle , has two electrocatheters (one installed in the atrium and the other in the ventricle) and better reproduces the heart's natural rhythm. It is the most commonly used type today because it maintains a more coordinated contraction, and is particularly suitable when connecting the two chambers of the heart, in individuals subject to blockages that prevent the impulse originating in the atrium from reaching the ventricle.

• Rate-responsive pacemaker

Increases or decreases the heart rate based on body activity, using different sensors (movement, breathing, etc.). It better simulates the heart's natural behavior during exercise.

• Pacemaker “on demand”

It activates only when the heart rate slows below a certain threshold, and if the heart beats normally, it remains in standby mode. It is considered the most modern standard.

• Leadless pacemaker

It's called this because it's a small device implanted directly into the ventricle, without a catheter. It reduces complications related to leads, although it's not suitable for everyone (but this is a doctor's assessment), and it offers several advantages. The leadless device eliminates the need for a surgical pocket and there are no external "pathways" for bacteria, thus reducing the risk of difficult-to-treat infections. Its implantation leaves no visible scars , and it lasts longer than conventional pacemakers (15 years instead of 10). Finally, it doesn't cause discomfort during sports. On the other hand, the leadless pacemaker does have some drawbacks. First of all, it currently only stimulates the right ventricle (so it's single-chamber), it can't perform more complex functions (such as atrioventricular synchronization or CRT), and removal or replacement can be more complex. Not to mention the cost: it can be up to five times more expensive than a conventional pacemaker. The wireless device alone costs between 3,000 and 6,000 euros, while the traditional one costs between 1,000 and 3,000 euros.

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