Artificial cardiac pacemaker

Artificial Cardiac Pacemaker

An artificial cardiac pacemaker is a medical device that generates electrical impulses delivered by electrodes to contract the heart muscles and regulate the electrical conduction system 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. Modern pacemakers are externally programmable and allow the cardiologist to select the optimum pacing modes for individual patients.

History

The development of the artificial pacemaker has involved several innovations over the years. The first external pacemaker was developed in 1950 by Canadian electrical engineer John Hopps, based on research by Wilfred Bigelow and John Callaghan. The first implantable pacemaker was introduced in 1958 by Swedish inventor Rune Elmqvist and surgeon Åke Senning.

Types

There are several types of pacemakers, classified by their function:

• Single-chamber pacemakers stimulate either the right atrium or the right ventricle.
• Dual-chamber pacemakers can stimulate both the atrium and ventricle and can coordinate the timing between the two (atrioventricular synchrony).
• Biventricular pacemakers, also known as Cardiac Resynchronization Therapy (CRT) devices, are used for the treatment of heart failure by coordinating the contractions of the left and right ventricles.

Indications

Pacemakers are indicated for use in patients with arrhythmias such as:

• Bradycardia - abnormally slow heart rates
• Heart block - a delay or complete block of the heart's electrical impulse from reaching the ventricles
• Atrial fibrillation with slow ventricular response - a common type of arrhythmia where the atria beat irregularly and often rapidly, but the response of the ventricles is slow due to blockage of electrical impulses

Components

An artificial cardiac pacemaker consists of two main components:

• The pulse generator, which includes the battery and the electronics that control the heartbeat.
• The leads (or electrodes), which deliver the electrical impulse from the pulse generator to the heart muscle.

Procedure

The implantation of a pacemaker is a surgical procedure that usually requires local anesthesia. The leads are inserted through a vein and guided into the heart, while the pulse generator is placed under the skin in the chest or abdomen.

Risks and Complications

While pacemaker implantation is generally safe, there are risks and potential complications, including:

• Infection at the implant site
• Swelling, bruising, or bleeding
• Damage to the blood vessels or nerves near the pacemaker
• Pneumothorax (collapsed lung)
• Pacemaker malfunction

Living with a Pacemaker

Patients with pacemakers should have regular follow-ups to ensure the device is functioning properly. Certain precautions should be taken, such as avoiding strong electromagnetic fields and informing medical personnel about the pacemaker before any medical procedure.

Future Directions

Advancements in pacemaker technology continue to evolve, focusing on increasing the longevity of the device, reducing the size, and improving the functionality to more closely mimic the heart's natural rhythms. Leadless pacemakers and biocompatible materials are among the innovations being explored.