Pacemaker Implantation

Your heart has its own natural pacemaker, the sinus node, which sets the rhythm, and an electrical pathway that carries each signal from the upper chambers, the atria, to the lower chambers, the ventricles. When the sinus node slows down or the pathway is blocked, the heart may beat too slowly to supply the body with enough blood. A pacemaker has two parts: a pulse generator, which is a small sealed metal case containing a battery and a tiny computer, and one or more leads that run through a vein into the heart. A single-chamber device has one lead, while a dual-chamber device has two, one in the right atrium and one in the right ventricle, so the chambers keep working in their natural sequence. Leadless pacemakers are capsules about the size of a large vitamin pill, placed directly inside the right ventricle through a vein in the groin. Most devices pace only when needed and stay quiet while your own rhythm is adequate.

A pacemaker is recommended when a slow or interrupted heart rhythm causes symptoms or carries a risk of sudden collapse, and the cause cannot be corrected. The two main reasons are sick sinus syndrome, in which the natural pacemaker fires too slowly or stops for several seconds, and heart block, in which signals fail to pass from the upper to the lower chambers. Higher grades of heart block are often treated with a pacemaker even when symptoms are mild, because the rhythm can suddenly worsen. Other reasons include a slow pulse combined with atrial fibrillation, some types of fainting linked to sudden slowing of the heart, and heart block after heart surgery or a valve procedure. Before deciding, doctors look for reversible causes, such as medicines that slow the heart, an underactive thyroid or salt imbalances in the blood. A related device, cardiac resynchronisation therapy, uses an extra lead to coordinate both ventricles in selected people with heart failure.

The procedure is done in a cardiac catheterisation or device laboratory, usually under local anaesthesia with light sedation, so you are relaxed but breathing on your own. An antibiotic is given beforehand to lower the risk of infection. The cardiologist makes a cut of about 4 to 6 centimetres below the collarbone, usually on the left, and passes the leads through a vein into the heart, guided by live X-ray. The tip of each lead is fixed to the heart wall with a tiny screw or small tines, and the leads are tested to confirm that they sense the heart's own signals and pace it reliably. The pulse generator is then connected and placed in a pocket under the skin, or occasionally under the chest muscle, and the wound is closed with dissolvable stitches or skin glue. A leadless pacemaker is instead delivered through a vein at the top of the leg, leaving no chest wound. The whole procedure usually takes about one to two hours.

Most people who need a pacemaker are suitable for one, including older adults, because the procedure is done under local anaesthesia and puts little strain on the body. The decision rests on your symptoms and on proof that a slow rhythm is the cause, usually from an ECG, a 24-hour or longer heart monitor, an echocardiogram and blood tests; some people need a small implantable loop recorder to capture rare episodes. Before the procedure your team reviews your medicines: blood thinners may be continued, paused or adjusted depending on the type, and diabetes medicines may need changes around fasting. You will usually be asked not to eat or drink for about six hours beforehand. Any active infection, including skin or dental problems, should be treated first. For international patients, ECGs, monitor recordings and reports can usually be reviewed remotely, so the need for a pacemaker and the device type are agreed before you travel.

Most people go home the day after the procedure, once a chest X-ray, a wound review and a device check confirm that the leads are in place and working. For about four to six weeks you are asked not to raise the arm on the device side above shoulder height, not to lift heavy objects and not to swing or push hard with that arm, so the leads can settle into the heart wall. Walking and light daily activity can resume within days. Driving rules after a pacemaker vary between countries and depend on why the device was fitted, so check the rules where you live. Plan to stay abroad for about 2 to 7 days, so the wound is checked and the device is tested before the flight. Carry your device identification card at airport security. Many modern pacemakers support remote monitoring, which sends device data from home to a clinic, and your team should arrange a device clinic near you that can check your model.

Pacemaker implantation is a routine, well established procedure, but like any procedure it carries risks. The most common problem is bruising or a collection of blood around the device, which usually settles without treatment. Less common complications include a lead moving out of position in the first weeks, which needs a short repeat procedure, a puncture of the lung during vein access that occasionally needs drainage, infection of the device, which may mean removing the whole system, and rarely a tear in the heart wall. Leadless pacemakers avoid the chest pocket and lead problems, but carry their own small risks at the groin and inside the heart. Most people notice that dizziness, fainting and tiredness caused by a slow rhythm improve within days. Most modern pacemakers are MRI-conditional, meaning scans are possible under specific settings agreed with the device team. The battery commonly lasts many years, often around 8 to 12 depending on how much pacing you need, and is then replaced in a shorter procedure.