A pacemaker is a small electrical device that is implanted beneath the skin into the chest wall and is used to treat various cardiac arrhythmias. It transmits electrical impulses to the heart if this is beating too slowly or stops, and intervenes with targeted impulses or small shocks to ensure a regular rhythm if it is beating too rapidly.
The pacemaker at a glance
The pacemaker is a battery-powered, microformat electronic system. The implantable cardiac device is equipped with a receiver and a transmitter. The receiver registers cardiac activity and records the heartbeat, while the transmitter sends out electrical impulses to set the heart’s rhythm or intervene in the event of imminent, dangerous cardiac arrhythmias.
The pacemaker can also be used for diagnostic purposes. By continuously capturing and recording the heartbeat, cardiac arrhythmias can be detected, which are otherwise difficult to document using a conventional ECG (electrocardiogram).
Types of pacemakers
Different pacemakers are used depending on the type of cardiac arrhythmia or heart disease.
- Single-chamber pacemaker: VVI pacemakers and AAI pacemakers are single-chamber systems with an electrode located in either a ventricle (VVI) or an atrium (AAI). Single-chamber systems are used for atrial fibrillation and impulse disturbances in the sinus node. The sinus node is the heart’s clock.
- Two-chamber pacemaker: The DDD pacemaker is a two-chamber system with one electrode in an atrium and a second electrode in a ventricle. If needed, the pacemaker can both stimulate the heart and slow it down. This means that the frequency can be adapted to the needs of the patient and the strain on the heart.
- Cardiac resynchronisation therapy (CRT): The CRT heart pacemaker is a three-chamber system with an additional electrode in the left ventricle. It is mainly used in patients with heart failure and stimulates the right and left ventricles simultaneously with electrical impulses. This makes it possible to achieve a synchronous heartbeat and improve cardiac output.
- Implantable cardioverter-defibrillators (ICD): Implantable defibrillators monitor heart rhythm and can transmit shocks in the event of potentially fatal rapid heartbeats (e.g. ventricular fibrillation) in order to restore normal heart rhythm.
Treatment goal
Pacemakers are used to treat cardiac arrhythmias and intervene if the heart is beating too slowly (bradycardia) or too quickly (ventricular tachycardia, ventricular fibrillation). The modern systems can intervene in the heart’s electrical activity with great precision to ensure normal cardiac activity.
Atrial fibrillation
Single-chamber systems are usually used for atrial fibrillation. These set the pace if the atrium is beating in an uncoordinated manner. Where this condition appears simultaneously with a disturbance in the transmission from the atrium to the ventricle, a two-chamber system is used.
Bradycardia
A heartbeat that is too slow, known as bradycardia, is the most common cardiac arrhythmia requiring the use of a pacemaker. Disturbances in the transmission from the atrium to the ventricle (atrioventricular block, or AV block), sick sinus syndrome and atrial fibrillation are all illnesses that can lead to bradycardia.
Ventricular fibrillation
People who are at risk of life-threatening ventricular fibrillation or who have ever survived ventricular fibrillation will have a pacemaker implanted to act as a defibrillator and intervene immediately if there is a risk of ventricular fibrillation.
Heart attack
In some cases, a pacemaker is also needed after a heart attack or heart operation if the heart attack or surgery has affected electrical signal transmission in the heart.
Resynchronisation therapy
Pacemakers are also used for resynchronisation therapy in patients with cardiac insufficiency (heart failure). If a patient with cardiac insufficiency is also experiencing a disturbance in the electrical activity of the heart muscle, the heart muscle will no longer contract completely synchronously and cardiac output will decrease. In this case, a CRT heart pacemaker can help and resynchronise the heart muscle.
Procedure for a pacemaker operation
During pacemaker or defibrillator implantation, the affected area below the collarbone is first placed under local anaesthesia. The device is then inserted underneath the skin. The probes (electrodes) are gently pushed through a vein and forwards to the corresponding ventricle and fixed there for the purposes of monitoring and, if necessary, regulating heart activity.
The pacemaker is then checked to make sure it is functioning. If everything is working properly, the incision is closed. The entire intervention usually takes about an hour. Following a final inspection of the system and last check-up, the patient can usually leave the hospital the next day.
Preparation and precautions
Before pacemaker implantation, a thorough diagnosis is required to precisely determine the necessity, type and urgency of the intervention. Diagnostic tests such as an ECG are used to analyse the heart rhythm so that the pacemaker can be tailored specifically to the individual requirements of the patient’s cardiac arrhythmia.
Before the surgery, the patient should stop taking solid food for six hours, and refrain from drinking any clear fluids for two hours beforehand. Blood-thinning medications should be paused early on in consultation with the attending doctor in order to minimise the risk of bleeding during the intervention.
Assumption of costs for a pacemaker
The costs for a pacemaker are covered by compulsory basic health insurance. This also includes regular check-ups of the pacemaker.
Recovery and aftercare
After the surgery, patients receive a pacemaker ID card that they must carry with them at all times.
Until the skin wound has healed completely, they should avoid placing excessive strain on the chest caused by, for example, lifting heavy loads. In addition, the patient should skip the wound during personal hygiene for a few more days.
Given that it takes some time for the pacemaker and electrodes to become firmly ingrown, patients should refrain from strenuous physical activities at first.
They are also not permitted to drive a car for a week after insertion of the pacemaker. If the pacemaker was implanted following cardiac arrest, it may be necessary to wait longer before driving to make sure that the risk has been ruled out completely.
Service life of a pacemaker
Depending on the type of pacemaker and heart disease, the function of the implanted systems must be checked regularly at intervals of six months to one year. If adjustments are needed, the pacemaker can be programmed externally. Depending on the strain, the service life of the lithium battery is between 6 and 10 years. After this, the pacemaker has to be replaced.
Magnetic fields and electrical installations can impair pacemaker function. For this reason, individuals with a pacemaker are fully informed of possible risks, in particular in relation to:
Alcohol consumption
Alcoholic beverages can cause cardiac arrhythmias. Alcohol consumption should be therefore limited or, ideally, stopped altogether.
Electronic devices
Electronic devices generate magnetic fields that can impair pacemaker function. In particular, devices with strong magnets or intense magnetic fields, such as induction stoves, can cause disturbances. After the intervention, patients are given detailed instructions explaining what to watch out for and which devices to avoid. In general, maintaining a minimum distance of 30 cm between electronic devices and the pacemaker is recommended at all times.
Travel and airport security checks
When at the airport, the pacemaker ID card must be presented, as the device can trigger an alarm during the security check. From a certain depth, deep-sea diving can damage the pacemaker due to the water pressure. Dives deeper than 5 m are therefore not recommended.
Potential complications
Pacemaker implantation is a very common routine operation. As with all surgical interventions, complications can occur in rare cases. The skin wound may become inflamed or bruised. Sometimes the probes are placed incorrectly. Experiencing hiccups after treatment or a tingling sensation in the arm may indicate incorrect placement. Pacemaker syndrome with low blood pressure, shortness of breath and dizziness is occasionally seen in patients with VVI pacemakers. In such cases, the probes need to be re-anchored or the pacemaker adjusted.
It is generally possible to lead a largely normal life with a pacemaker. The pacemaker can help to improve quality of life and reduce the health risks brought on by cardiac arrhythmia, in turn having a positive effect on life expectancy.
