Cardioversion is the attempt (doesn't always work) to restore the heart to normal sinus rhythm (NSR) or regular sinus rhythm (RSR) from a rhythm that is unacceptable.or causing hemodynamic instability. This is done chemically by medications that change the heart rhythm or mechanically by electrical cardioversion. Note that this is much different than defibrillation. Electrical cardioversion is not used in individuals that need defibrillating, it is more of a synchronized (by the computer) delivery of energy (joules) to the chest wall. The amount of energy used in electrical cardioversion is significantly less than in defibrillation. Further, electrical cardioversion is only used for non lethal arrhythmia's like atrial flutter, atrial fibrillation (AF) , or supraventricular tachycardia (SVT). Medications are usually tried first, electrical cardioversion may be used if the heart rhythm is unresponsive to the medications.
Cardioversion is a medical procedure for converting an abnormal heart rhythm to a normal one. There are two different ways of doing this - using electrical shocks or drugs.
Procedure using electrical shock, called synchronized electrical cardioversion works by administering measure amount of current to the heart at specific times during the cardiac cycle.
Drug based cardioversion, called orpharmacologic or chemical cardioversion, uses drugs called antiarrhythmia medication. This kind of cardioversion is also used for maintaining cardiac rhythm after electrical cardioversion.