Artificial pacemaker

Artificial Pacemaker

An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart or to reproduce the rhythm of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or there is a block in the heart's electrical conduction system.

History

The development of the artificial pacemaker began in the 1950s. The first successful implantation of a pacemaker was performed by Dr. Åke Senning and engineer Rune Elmqvist in 1958. Since then, pacemaker technology has advanced significantly, with modern devices being smaller, more reliable, and capable of more complex functions.

Indications

Artificial pacemakers are indicated for various conditions, including:

• Bradycardia, where the heart beats too slowly.
• Heart block, a condition where the electrical signals are partially or completely blocked between the atria and ventricles.
• Atrial fibrillation with slow ventricular response.
• Heart failure with certain types of cardiomyopathy.

Components

A typical pacemaker system consists of two main components:

• Pulse Generator: This is the device that generates the electrical impulses. It contains a battery and electronic circuitry enclosed in a metal case.
• Leads: These are insulated wires that deliver the electrical impulses from the pulse generator to the heart muscle. They also sense the heart's electrical activity and relay this information back to the pulse generator.

Types of Pacemakers

Pacemakers can be classified based on their function and the number of leads:

• Single-chamber pacemaker: Has one lead placed in either the right atrium or right ventricle.
• Dual-chamber pacemaker: Has two leads, one in the right atrium and one in the right ventricle, allowing for coordinated pacing of both chambers.
• Biventricular pacemaker: Used in cardiac resynchronization therapy (CRT), it has three leads to pace both ventricles and the right atrium, improving the heart's efficiency in patients with heart failure.

Implantation Procedure

The implantation of a pacemaker is a surgical procedure typically performed under local anesthesia. The leads are inserted through a vein and positioned in the heart under fluoroscopic guidance. The pulse generator is then placed under the skin, usually near the collarbone.

Risks and Complications

While pacemaker implantation is generally safe, potential risks include:

• Infection at the implantation site.
• Lead displacement or malfunction.
• Pneumothorax (collapsed lung).
• Bleeding or bruising.

Follow-up and Maintenance

Patients with pacemakers require regular follow-up to ensure the device is functioning correctly. This includes:

• Electrocardiogram (ECG) monitoring.
• Device interrogation to check battery status and lead function.
• Adjustments to the pacemaker settings as needed.

Advances in Pacemaker Technology

Recent advancements include:

• Leadless pacemakers, which are smaller and do not require leads.
• MRI-compatible pacemakers, allowing patients to undergo Magnetic Resonance Imaging safely.
• Remote monitoring capabilities, enabling healthcare providers to monitor pacemaker function remotely.

See Also

• Cardiac electrophysiology
• Implantable cardioverter-defibrillator
• Heart conduction system

References

• American Heart Association: Pacemaker
• NHS: Pacemaker Implantation