Pacemaker Implantation

A pacemaker treats a heart that beats too slowly. The device — a small generator containing a battery and circuitry — sits under the skin below the collarbone, connected to one or more thin leads threaded through a vein into the heart. It watches every beat and does nothing at all as long as your own rhythm is adequate. When a beat is missed or the rate falls too low, it delivers a small impulse that you do not feel.

Modern pacemakers adjust automatically: they can raise the paced rate when you are active and lower it at rest.

• Symptomatic bradycardia — a heart rate too slow to supply the body, causing fatigue, breathlessness, dizziness or fainting
• Heart block, where signals from the atria fail to reach the ventricles reliably
• Sick sinus syndrome, where the heart's natural pacemaker becomes unreliable, often alternating slow and fast rhythms
• Slow atrial fibrillation, or slowing caused by a medication that cannot be stopped
• After certain cardiac procedures or surgeries that affect the conduction system

Most devices are single-chamber (one lead, usually to the right ventricle) or dual-chamber (leads to both the right atrium and right ventricle, coordinating the two the way a normal heart does). A leadless pacemaker is a self-contained capsule implanted directly inside the right ventricle through a vein in the leg, with no chest incision and no leads — an option for selected patients. A biventricular device is a different therapy, described under cardiac resynchronization therapy.

Implantation typically takes one to two hours. You will have nothing to eat or drink after midnight, and instructions on holding blood thinners. Sedation is given along with local anesthetic — most patients are drowsy rather than fully asleep and are comfortable throughout. A small incision is made below the collarbone, the leads are guided into position through a vein under X-ray, tested, and connected to the generator, which is placed in a pocket beneath the skin. Antibiotics are given to reduce infection risk.

Most people stay one night. A chest X-ray and a device check confirm lead position before discharge.

• Keep the incision clean and dry; follow your team's guidance on showering, and do not submerge the site
• Avoid raising the arm on that side above shoulder height, and avoid heavy lifting, for about four to six weeks while the leads scar into place
• Expect bruising, swelling and soreness for a week or two; the outline of the device under the skin is normal
• Call promptly for fever, or redness, warmth, drainage or increasing swelling at the site — these can indicate infection, which in an implanted device is treated urgently

You will carry a device identification card and be checked periodically, largely through remote monitoring from home. Batteries typically last around 8 to 12 years; replacing one involves changing the generator, usually leaving the existing leads in place.

Everyday electronics, microwaves and airport security are safe. Keep cell phones and portable music players out of a breast pocket directly over the device, and keep strong magnets away from it. Tell any clinician you have a pacemaker before an MRI — most current devices are MRI-conditional, but the scan requires specific preparation. Arc welding and some industrial equipment warrant a conversation with your electrophysiologist.