Electrical Cardioversion

Electrical cardioversion is a procedure that is used to treat certain arrhythmias. We use electrical discharge, which goes through the patient's chest for a short time. It sounds dangerously, but it is in fact a very simple and painless procedure.


The electrical cardioversion is performed in continuously monitored patient in horizontal position. The procedure is performed under short general anesthesia. When the patient is asleep, the doctor uses electrical defibrillator, attaches its pads covered with special conductive gel to the patient's chest and activates it. After activation, the device evaluates the patient's heartbeat and in the right moment it emits an electrical signal which spreads between the pads through the patient's chest. This discharge should "reset" the arrhythmia and allows establishing normal heart rhythm.


The electrical cardioversion is usually done in heart rhythm disorders that arise in the cardiac atria (so-called supraventricular arrhythmias), typically in atrial fibrillation. We could try to solve these rhythm disturbances pharmacologically, but this method is often not successful. Whether to perform electric cardioversion, or keep the arrhythmia, we decide individually, according to the exact type of rhythm disorder, its clinical manifestations, the patient's overall health condition, etc. Cardioversion should be done in rhythm disorders that overload the patient's heart, threaten to cause heart failure and that does not respond to medication.


Electrical cardioversion should be done on empty stomach. This is especially because of the need of general anesthesia to prevent aspiration of gastric content.

The patient should know that weak sedative effects of the general anesthesia may last for some time after the general anesthesia and that day it is advised not to drive a motor vehicle or perform any activity demanding increased attention.


Electrical cardioversion should not be performed in a patient with supraventricular arrhythmia lasting an unknown time period. Supraventricular arrhythmias can cause abnormal movement of heart atria and this leads to occurrence of local atrial blood clots. The electrical discharge can break off these blood clots. They may move in the bloodstream into carotid arteries and deep into the brain, causing ischemic stroke. Therefore we can perform a electrical cardioversion only, if:

  • we are sure that the rhythm disorder last less than 48 hours. The blood clots do not form in so short time.
  • we perform a transesophageal echocardiography, which rules out the presence of blood clots in heart cavities.


The electric version is fast, efficient and totally painless solution of many types of arrhythmia. It is great in acute conditions when pharmacotherapy in not effective and the patient is threatened by acute cardiovascular failure.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Contact: jiri.stefanek@seznam.cz
 Sources: basic text sources