Overview

A pacemaker is a small electronic device that helps regulate your heart rate. If your heart beats too slowly or irregularly, the pacemaker sends tiny electrical impulses to make your heart contract at a regular and adequate rate. This device is implanted under the skin in your chest through a minor surgical procedure.

Thanks to a pacemaker, your heartbeats become stable, ensuring your brain and organs receive enough blood. As a result, your quality of daily life improves significantly.

What Is a Pacemaker?

A pacemaker is a metal device placed in the upper chest, just beneath the collarbone. It is about the size of a small matchbox and contains a battery and electronic circuits.

Thin insulated wires called leads (electrodes) run from the device through your veins to the heart muscle, where they deliver the electrical impulses that trigger each heartbeat.

Modern pacemakers are highly advanced. They constantly monitor your heart’s electrical activity and activate only when necessary. Some models can automatically adjust your heart rate according to your physical activity level — increasing it during exertion and lowering it at rest — so your heart rhythm remains appropriate in all conditions.

How Does a Pacemaker Work?

Your heart has its own natural electrical system. A structure in the right atrium called the sinus node generates regular electrical signals. These signals spread through the heart muscle, causing it to contract. Each signal produces one heartbeat.

Sometimes, this natural system malfunctions. The sinus node may not generate signals fast enough, or the signals may not reach the lower chambers of the heart. As a result, the heart beats too slowly or pauses.

The pacemaker corrects this problem. It continuously measures your heart’s electrical activity. When a normal heartbeat occurs, the device stays silent. But if a beat is delayed or fails to appear, the pacemaker sends its own impulse to stimulate the heart muscle. This keeps your heart rate within a safe range.

Modern devices also include intelligent sensors that detect movement. They increase your heart rate when you walk, climb stairs, or exercise, and slow it down again when you rest. This allows the pacemaker to mimic your body’s natural rhythm as closely as possible.

Types of Pacemakers

Pacemakers are classified according to how many chambers of the heart they stimulate. Each type is designed for specific rhythm problems.

• Single-chamber pacemaker: This type stimulates only one chamber of the heart, usually the right ventricle. It is used when the sinus node works normally but electrical conduction is slow. It is the simplest form, with a single lead.
• Dual-chamber pacemaker: This type connects to both the right atrium and the right ventricle with two leads. It helps coordinate the timing between the atria and ventricles. It is preferred when both the sinus node and conduction system are affected.
• Three-chamber pacemaker (biventricular or CRT): Used in patients with heart failure. Leads are placed in the right atrium, right ventricle, and left ventricle. The device synchronizes contractions of both ventricles — a therapy known as cardiac resynchronization therapy (CRT) — improving the heart’s pumping efficiency.
• Leadless pacemaker: This is the newest pacemaker technology. Unlike traditional systems, no generator pocket or leads are implanted under the skin. The tiny capsule-shaped device is placed directly inside the heart (usually the right ventricle) through a catheter inserted via the groin vein.
  Because there are no wires, the risk of infection or lead-related complications is much lower. The procedure is quick and minimally invasive. Leadless pacemakers are mainly used as an alternative to single-chamber systems.
• Implantable cardioverter-defibrillator (ICD): Some special devices not only correct slow rhythms but also detect and stop dangerous fast arrhythmias such as ventricular tachycardia by delivering an electric shock. These are called ICDs.

What Does a Pacemaker Do? Why Is It Needed?

A pacemaker prevents the heart from beating too slowly and ensures efficient blood circulation.

• Bradycardia: A condition where the heart rate falls below 60 beats per minute. Mild bradycardia can be normal (e.g., in athletes), but severe bradycardia may cause fainting, chest pain, shortness of breath, dizziness, and fatigue.
• Sinus node dysfunction: Occurs when the heart’s natural pacemaker fails to work properly, often due to aging or underlying heart disease. If the sinus node cannot produce adequate impulses, a pacemaker is required.
• Atrioventricular (AV) block: A disturbance in the transmission of electrical signals between the atria and ventricles. When the signals are delayed or blocked, the heart rate slows down. In advanced AV block, a pacemaker is essential.
• Heart failure: When the heart cannot pump enough blood and electrical conduction is impaired, a biventricular pacemaker can relieve symptoms and improve quality of life.
• Risk of sudden cardiac death: After a heart attack, cardiomyopathy, or certain genetic conditions, some patients have a high risk of lethal arrhythmias. In these cases, an ICD device both regulates heart rate and stops fatal rhythms with an electric shock.

How Is a Pacemaker Implanted?

Pacemaker implantation is performed in an electrophysiology lab or operating room, usually under local anesthesia. The area is numbed; the patient remains awake but does not feel pain. A mild sedative may be given for relaxation.

First, a small incision is made in the upper chest, typically on the left side. The physician creates a small pocket under the skin or muscle to hold the device.

Next, a thin needle is inserted into a vein beneath the collarbone, and the leads are advanced through the vein into the heart. Using live X-ray imaging (fluoroscopy), the doctor guides the leads to the correct position and secures their tips to the heart wall.

Electrical tests confirm proper signal transmission. Once verified, the other ends of the leads are connected to the pacemaker, which is placed inside the pocket. The incision is then closed with stitches.

The procedure usually takes 1–2 hours. Most patients go home the same day or the next. Mild pain or bruising at the incision site for a few days is normal.

What Happens If a Pacemaker Is Not Implanted When Needed?

If a pacemaker is recommended but not implanted, serious health problems may occur.

In severe bradycardia, the heart cannot pump enough blood. The brain receives less oxygen, leading to fainting or sudden falls, which may cause head injury or accidents.

In advanced AV block, the heart can stop completely. The ventricles may generate a very slow “escape rhythm,” but it is unreliable and may fail suddenly, causing cardiac arrest.

In heart failure, lack of appropriate therapy leads to worsening symptoms such as shortness of breath, leg swelling, and fatigue. Hospitalizations increase and life expectancy decreases.

Recurrent fainting episodes make everyday activities unsafe, including driving or living alone.

Risks of Pacemaker Implantation

Pacemaker implantation is generally safe, but as with any surgical procedure, some risks exist. Most complications are mild and easily treatable.

• Bleeding: Bleeding can occur during or after surgery at the incision site. The risk is slightly higher if you take blood thinners. Major bleeding is rare but may require additional treatment.
• Infection: An infection may develop at the incision site. Signs include redness, pain, swelling, or discharge. Early detection allows treatment with antibiotics; severe infections may require removal of the device.
• Pneumothorax: Accidental injury to the lung membrane can allow air to leak around the lung, partially collapsing it. Mild cases resolve on their own; severe ones may need a chest tube.
• Lead problems: Occasionally, a lead may be misplaced or dislodged over time, causing the device to malfunction. A minor corrective procedure can fix it. Rarely, a lead may perforate the heart wall, requiring urgent care.
• Fluid or blood collection: Fluid (seroma) or blood (hematoma) may accumulate around the device pocket. Small collections usually absorb spontaneously; larger ones can be drained.
• Allergic reaction: Rarely, the body reacts to device materials, causing redness, itching, or rash.
• Cardiac tamponade: Extremely rare — bleeding into the sac around the heart can compress it, requiring emergency drainage.

Most complications are mild and fully resolve with appropriate management.

After Pacemaker Implantation — What to Watch For

To ensure your pacemaker functions well and lasts long, follow these recommendations:

• Keep the incision area clean and dry. Avoid bathing for the first 48 hours. Cover the area with a waterproof dressing when showering.
• Avoid lifting heavy objects. Do not raise the arm on the pacemaker side above shoulder level for 4–6 weeks — this allows the leads to anchor securely inside the heart.
• Most everyday electronic devices are safe. However, do not carry your mobile phone in the pocket over the device and keep it at least 15 cm (6 in) away when talking.
• Before an MRI scan, always inform medical staff that you have a pacemaker. Most new devices are MRI-compatible, but older ones are not.
• Airport security scanners do not harm pacemakers, but they may trigger alarms. Show your pacemaker ID card to security staff.
• Stay away from welding machines, strong magnets, or large electric motors. Home appliances like blenders, vacuum cleaners, or electric razors are generally safe.
• Schedule regular check-ups. The first one is usually 2–4 weeks after implantation, then at least once a year. During visits, the device’s battery, leads, and settings are checked. Battery life is typically 7–15 years, and the generator is replaced when nearing depletion.

Contact your doctor immediately if you experience:

• Dizziness, fainting, or palpitations
• Swelling, redness, discharge, or fever around the device site
• Persistent hiccups or muscle twitching

Maintain a heart-healthy lifestyle: exercise regularly, eat a balanced diet, quit smoking, and manage stress. These habits protect both your heart and your pacemaker.