Types of Treatments by a Cardiac Defibrillator

(June 15th, 2005) - Different types of treatments can be delivered by a cardiac defibrillator to stop an arrhythmia. A combination of treatments is also possible.

Antitachycardia Pacing
If your arrhythmia is regular but fast, the defibrillator can deliver and series of small, rapid electrical impulses, for a period of around one second. You may feel a fluttering sensation in your chest but normally you will not feel this type of pacing therapy. The aim of the therapy is to stop the arrhythmia and return the heart to its normal rhythm.

Cardioversion
If your arrhythmia is regular but too fast, the cardiac defibrillator can deliver a low-energy shock. This is normally felt as a 'thump' or 'punch' to the chest (10 to 20 joules). The aim is, once again, to stop the arrhythmia and return the heart back to its normal rhythm.

Defibrillation
For arrhythmia that are very fast and irregular, a high-energy shock may be delivered by the cardiac defibrillator. Many patients faint or lose consciousness shortly after a very fast arrhythmia therefore they do not feel the shock. For patients who do not faint, the shock has been described as a 'kick in the chest'. It is generally sudden and the feeling lasts for only a few seconds (the shock can give up to 35 joules).

Antibradycardia Pacing (cardiostimulator)
When the natural rhythm of a patient is too slow, the cardiac defibrillator delivers very low-energy electrical impulses, which are generally not felt. This is the cardiostimulator part (or pacemaker) that is included in all defibrillators. 

Annie Lehouillier
Infirmière bachelière
Clinique des cardiostimulateurs et des défibrillateurs
Hôpital Laval