Pacemaker is a device that is usually used to solve heart rhythm disorders that have the character of bradycardia (i.e. heart beat below 60 per minute).


Pacemaker is a small metal box with electrodes. The pacemaker can regularly produce electrical discharges and those are by the electrodes transmitted to the heart muscle where they cause contractions. The frequency of these signals can be modified according to the needs of the patient and the doctor. In addition, many types of pacemakers are able to monitor the patient's heart rate and work only when needed or leave the patient's own rhythm. This is advantageous in a person who suffers only from bouts of bradycardia. Does such person have a normal heart rate at the time? The pacemaker monitors the situation and does nothing. When the heart rate drops below a certain value (which can be preset), the pacemaker activates and begins to transmit impulses.


It should be emphasized that the stimulator can not cope with heart rhythm disorders that are associated with a rapid heartbeat. The pacemaker can "only" ensure that the heart does not beat too slowly, but that is all. Normal pacemaker can not help when the patient begins to suffer from a rapid atrial fibrillation or even ventricular fibrillation.


The stimulator is inserted subcutaneously into the chest right under the clavicle and its electrodes should be in close contact with the heart muscle. The procedure is performed under local anesthesia and after the insertion of the pacemaker, an ECG is performed to assess the pacemaker's function. The wound is small and it is closed by few stitches. For one day after the procedure, the patient should obey strict bed rest and not elevate the upper hand at the side of pacemaker implantation.


Patients with implanted pacemaker are regularly checked by a cardiologist who checks the status and function of the device and indicates replacement of the battery when needed. The presence of the pacemaker can be usually determined from the ECG, where there are special vertical lines - electric discharges of the device.


The battery of the pacemaker should be replaced every few years. The procedure is a little bit similar to the introduction of a new pacemaker. The electrodes stay intact and the doctor just replaces the old metal box for another. The procedure is again performed under local anesthesia. However, as the electrodes are not changed, strict bed rest is not necessary after the intervention.


The pacemaker should not come into close contact with strong magnetic field, which is the problem in magnetic resonance imaging. For this reason, pacemaker presence is a contraindication for MRI examination. People with pacemakers are also advised not to carry a mobile phone close to the pacemaker and when making a call, it is advisable to hold the phone near the ear opposite to the implanted pacemaker.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources