A pacemaker allows many heart patients to live a symptom-free life. Bradycardic arrhythmias are regulated by this little medical miracle and the risks of the procedure are minimal. How exactly a pacemaker works and how it is inserted is explained in this article.
What is a pacemaker??
A pacemaker is an impulse generator for the heart muscle. Today’s devices are about the size of a two-euro piece and are implanted in the chest cavity. It depolarizes the heart muscle through electrical stimulation. This triggers a contraction of the heart muscle. Primarily, a pacemaker is used to correct heart rhythm problems (arrhythmias) in which the heartbeat is too slow – known as bradycardias. There are about three million active pacemakers worldwide and more than 600.000 are re-deployed annually. There are different versions of pacemakers. They are selected based on underlying heart disease.
This pacemaker works with an electrode. It controls and transmits the signals from the right ventricle or atrium to the pulse generator. The single-chamber pacemaker is suitable for bradycardia patients whose sinus node delivers signals too slowly or no longer at all.
Dual chamber pacemaker
In a dual-chamber pacemaker, stimuli are delivered to the heart by two electrodes. One electrode stimulates the right atrium and the second the right ventricle. These devices come z.B. to be used in case of an AV-block.
The three-chamber pacemaker is implanted rather rarely. As the name suggests, a third electrode is used in this procedure. It leads via a cardiac vein into the left ventricle of the heart. The three-chamber pacemaker is needed when the heart muscle is very weakened. With the help of the three-chamber pacemaker, the heart chambers should contract as harmoniously as possible again. Therefore, this procedure is also called resynchronization therapy.
pacemaker or defibrillator?
Although pacemakers and defibrillators look very similar, they perform different tasks. The pacemaker is used when the heart beats too slowly. It permanently emits weak impulses in the normal heart rhythm. Every single impulse provides a new heartbeat.
A defibrillator, on the other hand, is implanted when the heart tends to beat too fast at times. In this case, the defibrillator delivers a stronger shock of electricity that stops the heart for a short time. Following this, the heart continues to beat at a normal rhythm. A defibrillator is also capable of acting as a pacemaker.
Cardiac pacemaker – reasons
The reasons pleading for a pacemaker are numerous. In particular, the presence of a bradycardic arrhythmia argues in favor of using. With the help of an ECG or. Long-term ECG’s can clarify an indication. If the recordings show longer pauses or blockages of the excitation conduction (e.g. AV block), a pacemaker can take over this function. This is also possible temporarily. A pacemaker does not automatically have to be implanted permanently. Symptoms such as dizziness and fainting combined with a low pulse can be indications of bradycardia. In this case, a physician should be consulted to determine the cause of the problem. Implantation of a pacemaker is sometimes indicated after a heart attack.
An overview of various indications that make a pacemaker mandatory:
in combination with complaints like dizziness
- conduction disturbances (AV block) even without symptoms
- Combined arrhythmias in the form of bradycardia-tachycardia syndrome
- Inappropriate pulse increase during stress (chronotropic incompetence)
Pacemaker – Function
A pacemaker is composed of an energy source, circuit and electrodes. Both the energy source and the circuitry are contained in a metal housing. Lithium-ion batteries are used as an energy source. They have an operating life of five to fifteen years. In addition, a pacemaker has a connector. The plugs of the pacemaker probes are fixed in it. The pacing electrodes consist of a connector, cable and electrode head. They connect the heart muscle to the pacemaker unit.
Devices with a microchip circuit allow pacing to be programmed via radio waves through a transcutaneous route. Modern pacemakers are capable of ensuring a steady pulse rate. They prevent cardiac arrhythmias or can regulate existing arrhythmias even without delivering an electric shock.
Pacemaker implantation – procedure
A local anesthetic is applied at the beginning of the procedure. It involves exposing a vein in the upper arm or the vein below the collarbone. This is done with the help of a small skin incision about 5 cm long or the vein is punctured with a hollow needle. A flexible, isolated electrode is inserted into the ventricle via this vein access. Under X-ray control, the physician is able to perform correct positioning. Once the desired position is reached, the electrode is fixed in place. This is the single-chamber system.
For a coordinated heart action it happens that another electrode is inserted in the right atrium. In this case it is called a two-chamber system. In the three-chamber system, a third electrode is attached to the left side of the heart via the vein. Now connect the free end of the electrode to an analyzer to be able to measure individual parameters of the electrode position. Once the values are in the desired range, the electrodes are fixed and connected to the pacemaker device.
For implantation, a pocket is formed in the fatty tissue below the collarbone. The pacemaker is positioned and fixed in this pocket. Finally, the wound is treated with self-dissolving sutures and a pressure dressing is applied. This prevents subsequent bleeding. Before the patient is discharged, the function of the pacemaker is checked and programmed according to the patient’s individual needs.
Pacemaker implantation – risks
Every surgical intervention involves certain risks. During pacemaker implantation, bleeding, thrombosis or nerve injury can occur. The formation of a hematoma (bruise) in the area of the wound is not a cause for concern, as it is usually gradually broken down by the body.
If redness and swelling in combination with fever occur in the area of the implanted pacemaker after the operation, an infection is present. Then regular control and observation by the doctor are necessary. If the infection is bacterial, it can be treated with antibiotics. However, infection rarely occurs.
There is a possibility of electrodes breaking or slipping out of place. As a result, the function of the pacemaker is disturbed. The consequences can take the form of vascular injuries or cardiac arrhythmias. This can be determined by checking the pacemaker.
Unintended electrical excitation of the diaphragm can cause the patient to hiccup. In this case there is an incorrect positioning of an electrode. If tingling occurs in the arm after the procedure, this is also an indication of an incorrect position of the electrode. The only remedy is another operation in which the placement of the electrode is corrected.
Reentry tachycardia is a complication caused by the pacemaker itself. Here, the device registers heart excitations that it has generated itself. As a result, it erroneously sends further stimuli, which result in tachycardia.
Pacemaker implantation – What to consider afterwards?
After the operation, most patients recover very quickly and can register a significant improvement in performance and quality of life. Initially, however, heavy physical activity should be avoided. The body needs a recovery period after surgery and both the pacemaker itself and the electrodes have yet to grow firmly into the tissue. Subsequently, however, everything that is beneficial to the patient’s well-being is permitted.
For people with pacemakers, there are still some things to consider in daily life:
- Keeping the following control appointments
- Always carry the pacemaker identification card with you – in case of an emergency, emergency personnel know how to act
- Some medical devices can interfere with the function of the pacemaker. MRIs, for example, can interfere with older pacemakers due to their strong magnet and can heat up their metal housing considerably
- When using electrical household appliances, keep a safe distance of 30 cm from the upper body
- Before purchasing larger, electrical devices, check the instructions for use for warnings
- When using a cell phone, the phone should be held to the ear opposite the pacemaker. In general, the distance between pacemaker and cell phone should always be at least 15 to 20 cm
- Informing airport (or similar) security personnel that you are wearing a pacemaker and presenting your pacemaker identification card. The control can then be done manually and without false triggering of the alarm and disturbance of the pacemaker
- In unfamiliar surroundings, look for any signage warning pacemaker wearers not to enter
This sign indicates that pacemaker or implanted defibrillator wearers are not allowed to enter a certain room.
Pacemaker life expectancy
A Dutch research group looked at survival rates after pacemaker surgery in a 2013 study. Until then, relatively little was known about life expectancy, especially in older patients. 481 patients over the age of 80 who had received a pacemaker were used for this study by the University Medical Center Utrecht. Complications as well as deaths were investigated and registered in a period of almost 6 years. This was contrasted with a comparison group of younger pacemaker patients. The complication rate was 9.8 percent two months after the procedure. It dropped again in the further course to 6.9 percent. It was found that the complication rate in patients over 80 years of age was not higher than in younger patients. The study thus came to the conclusion that life expectancy with pacemakers is identical to that without them.
Cardiac pacemaker – costs
The costs for the pacemaker as well as the pacemaker surgery are fully covered by the health insurance company.