Cardioversion is painful, according to the National Center for Biotechnology Information. The discomfort is comparable to a surgical incision, so deep sedation or general anaesthesia is used. This reduces pain sensations and also limits the body's stress response during the procedure.
Cardioversion is performed on an individual with arrhythmia, or abnormal heartbeat, Mayo Clinic explains. After electrodes are fixed to the chest, a doctor delivers electric shocks to the heart. Typically, the procedure promptly corrects the heart rhythm. In some cases, arrhythmia comes back within minutes or days. The procedure is repeated and heart-regulating medication is prescribed. Cardioversion is not normally used in emergency situations.