Heart pacemakers and defibrillators –implantations and checks

What is a heart pacemaker?

A heart pacemaker is a small device which is implanted under the skin in the area of the pectoral muscle, and monitors the heart rhythm, particularly in the case of a too slow heart rate. From this device, thin electrode cables lead via veins to the heart, where they are firmly connected to the muscle. In the event of pauses or too slow activity of the heart, the pacemaker can regulate the heartbeat by means of electronic pulses. The heart pacemaker permanently monitors the working of the heart, and only comes into action when it is needed. 

What is a defibrillator?

In contrast to the heart pacemaker, a defibrillator is implanted if the heart of a patient pumps too weakly, or when a patient has been revived because of severe heart rhythm disorders or when severe and rapid chamber actions (ventricular fibrillation or ventricular tachycardia) have occurred.

By means of a current impulse from the defibrillator, the heart is stopped, so that it then returns to its normal rhythm, thereby saving the life of the patient.
An implanted cardioverter defibrillator (ICD) automatically detects ventricular fibrillation, and reacts specifically to this process within a few seconds.

When is a heart pacemaker necessary?

In the case of certain heart rhythm disorders in which the heart beats too slowly, it may be necessary to implant a heart pacemaker. Due to diseases of the excitation and stimulus system of the heart, the heart rate may become so slow that the pumping function of the heart is no longer strong enough to supply the organs adequately with blood and oxygen. This can lead to performance deficiency, dizziness or even brief loss of consciousness (syncope). Too low a pulse may also be due to side effects of medications being taken by the patient for the regulation of blood pressure or rapid heart rhythm disorders. In this case too, the implantation of a pacemaker may become necessary.

When is a defibrillator necessary?

A defibrillator can be implanted in patients who suffer from ventricular fibrillation or life-threatening tachycardia caused by the heart ventricles (recurrent ventricular tachycardia), and this cannot be controlled with medications.

An ICD is also implanted following a survived “sudden cardiac death” or for reasons of prevention in patients with suspected risk of severe to fatal heart rhythm disorders with simultaneous heart muscle disease or coronary heart disease.


The function of a heart pacemaker or defibrillator and the electrodes must be checked at regular intervals, and at least quarterly. The intervals depend on the type of device and charging level of the battery. This must also be checked regularly. When the battery is too low, after five to eight years, it must be replaced.

The settings of the pacemaker/ICD may also need to be adjusted to new conditions, for example if heart rhythm disorders recur.

We can carry out this check in our private clinic for all common pacemakers and defibrillators on an out-patient basis.

Patients can also be additionally monitored by the “home monitoring” of the “Zentrum für Telemedizin”, which is accommodated in our Heidelberg Praxisklinik für Kardiologie für Kardiologie (HPK). This means that we at the HPK monitor the device information and activities on a daily basis, without the patient having to visit the private clinic. The HPK therefore offers the patient “double security”.


The check takes a few minutes.


Certain precautionary measures apply for people who carry heart pacemakers: they must keep away from strong magnetic fields, and keep electrical appliances at least 20 centimetres away from their body. In addition to after-care in our private clinic, we also offer training and consultation for people with heart pacemakers.