Pacemaker: single- vs dual-chamber, implantation and recovery

According to the EHRA patient website, a pacemaker consists of two parts:

• Generator: a small metal box containing the battery and the electronic circuit.
• Lead: a thin, insulated wire. It runs through a vein near the collarbone into a chamber of the heart.

The device constantly monitors the rhythm and sends a signal only when the heart beats too slowly. There may be 1, 2 or 3 leads, and there is also a leadless type.

This article is not about the decision on whether you need a pacemaker. It is about the types of device, implantation and the period after it.

According to EHRA, the type of device is chosen based on the rhythm problem:

• Single-chamber: one lead. If the signal comes from the sinus node (where the rhythm starts) but is slow, the lead is placed in the right atrium. If the rhythm is slow and does not start in the sinus node, for example in atrial fibrillation, it is placed in the right ventricle.
• Dual-chamber: two leads, in the right atrium and the right ventricle. It is used in AV block, that is, when the signal does not pass from the atrium to the ventricle. It coordinates these two chambers.
• Biventricular (CRT): two or three leads. Its job is different: to coordinate the work of the ventricles in heart failure.
• Leadless: only a generator, placed in the right ventricle through the femoral vein. It is only for people who need single-chamber pacing of that chamber alone.

According to the ACC summary of the 2021 ESC/EHRA guideline, in severe recurrent fainting, dual-chamber pacing may reduce recurrences in some patients older than 40 with recorded pauses. The choice is made by a specialist.

According to EHRA, preparation usually includes:

• blood tests;
• telling your doctor about any blood clotting disorder, blood thinners, allergies and possible pregnancy (some medicines may need to be stopped temporarily; the doctor decides this);
• sometimes washing the whole body with a special soap the day before;
• usually fasting from the night before, while taking your morning medicines with a little water.

The procedure is usually done under local anesthesia with sedatives. You stay awake, and general anesthesia is usually not needed. An antibiotic is given. A small incision is made on the left side of the chest, the lead is passed to the heart under X-ray guidance, and the device is placed under the skin near the collarbone.

Sources differ on timing. EHRA: usually 1–2 hours, a few hours of observation, home the same day or the next day. NHS: usually about one hour and usually one night in the hospital. Someone must take you home.

According to EHRA, the incision is a few centimeters long and hurts in the first days, and itching is normal. Keep it clean and dry. Unless your doctor tells you otherwise, you can usually return to work and everyday activities within one or two weeks.

Sources give different advice on arm movement:

• EHRA: there is no need to restrict the arm or keep it in a sling.
• NHS: for 4–6 weeks, do not raise your elbow above shoulder height, do not lift heavy things and do not do strenuous exercise; do not drive for at least the first week.

Ask your own doctor which advice to follow and keep to their instructions.

EHRA lists the risks without percentages:

• swelling, bruising and bleeding at the incision site: usually mild, more common with blood thinners;
• infection of the incision: serious, needs treatment right away;
• displacement of the lead: another procedure may be needed;
• infection of the device or lead: rare, serious, and it may appear long after implantation;
• pneumothorax or hemothorax (air or blood collecting around the lung): very rare;
• damage to a nerve or blood vessel: uncommon.

According to the ACC summary of the 2021 ESC/EHRA guideline, a significant collection of blood (hematoma) at the device site raises the risk of later infection almost eightfold. Infection is also more common in procedures to replace or upgrade the device.

Call your doctor quickly if you have: a fever above 38.5 °C, chills, redness or swelling over the device, fluid leaking from the incision, increasing pain, bleeding or the incision opening. Do the same if your earlier symptoms come back, if shortness of breath gets worse, or if you have chest pain or dizziness; if you faint or your symptoms are severe, do not wait for your doctor, call 103.

The checkup schedule differs between sources. EHRA: the first checkup at 2–12 weeks (the incision is examined and the device is checked with a programmer), then about once a year or more often. NHS: at about 6 weeks, at 3–6 months, then at least once every 12 months. Follow your own doctor's schedule. During a checkup, you may notice your heartbeat change briefly. In some places there is remote monitoring: the transmitter must be nearby, and it cannot reprogram the device.

The battery figures also differ. EHRA: the generator is usually replaced after 7–10 years, sometimes earlier. NHS: the battery usually lasts 6–7 years. Replacement is simpler than the first implantation, the leads are usually left in place if they work well, and people often go home the same day.