What is a cardioversion?

The term cardioversion describes the restoration of a normal heart rhythm (so-called sinus rhythm) in the presence of cardiac arrhythmias such as atrial fibrillation. There are two different methods of restoring a normal heart rhythm by means of cardioversion: electrical cardioversion by means of a defibrillator, also known as electric shock, and cardioversion performed by means of medication. Electrical cardioversion, colloquially known as electroshock, is performed with the help of a defibrillator under a short anaesthetic.

The defibrillator delivers electric shocks to the heart, which can synchronize the activity of the heart muscle cells again. The cells that no longer work in the same rhythm during atrial fibrillation are thus brought back into the same rhythm. Recurrence prophylaxis: The recurrence rate after electrical cardioversion is up to 75% after one year.

Therefore, the above-mentioned antiarrhythmic drugs are used for recurrence prophylaxis: Amidarone is the most effective, but is associated with many side effects and contraindications. Beta-blockers can also be used for relapse prevention.However, due to the danger of proarrhythmic (arrhythmia-promoting) effects, drug therapy is rarely indicated. In this case, two electrodes are attached to the chest and a direct current dose is used to restore the heart rhythm.

See defibrillation (same principle). The advantage is the immediate onset of the effect and the avoidance of the drug-related side effects. The disadvantage is the higher strain on the patient and the greater risk of embolic complications (e.g. stroke).

In addition to electrical cardioversion, drug therapy can also be used for atrial fibrillation. This form of cardioversion can be used without anesthesia and may even be performed by the patient himself/herself. Frequently used drugs are for example amiodarone, flecainide and ajmalin.

In patients without underlying heart disease, this is done with class I antiarrhythmics. Patients with heart disease are usually treated with amiodarone – a class III antiarrhythmic drug. The therapy is always carried out under inpatient supervision.

Patients who only have intermittent disorders may be given a “pill in the pocket” after training. They then simply take their tablet as needed, provided that they are in good heart health. Electrical cardioversion is used to restore a normal sinus rhythm in the heart muscle cells during atrial fibrillation.

The activity of the cells is synchronized and the pulse rate becomes stable. Depending on the cause of the atrial fibrillation, relapses, i.e. renewed atrial fibrillation, may occur after cardioversion. The probability is about 50%, so that every second patient gets atrial fibrillation again and the pulse rate becomes unstable. For this reason, treatment to prevent further cardiac arrhythmias should be initiated after electrical cardioversion, which consists of antiarrhythmic medication.