A nonemergency cardioversion treatment is also known as elective cardioversion. All patients undergoing elective cardioversion should refrain from eating or drinking for 12 hours prior to the procedure. They will be advised to avoid driving for 24 hours following the procedure due to any lingering effects of the sedatives. Some patients need to take an anticoagulant to lower the risk of blood clot formation. Patients who need anticoagulants take the medication for about three weeks prior to cardioversion treatment and four weeks following the procedure. In addition, antiarrhythmics may be prescribed before and/or after cardioversion to prevent a recurrence of the arrhythmia.

Elective cardioversion may be performed in a hospital or outpatient surgical facility. Patients will be asked to sign a consent form, wear a hospital gown, and to remove dentures, jewelry, nail polish and/or glasses.

During the procedure, the patient is first connected to a heart monitor and medications are administered intravenously to aid in relaxation and pain management. Two large, sticky patches containing electrodes are attached to the skin on the chest and are connected via insulated wires to a defibrillator. The device is calibrated by the physician to deliver the proper electrical charge for each patient. Both the intensity and the timing of the electrical charge are precisely controlled. This is known as external cardioversion. Internal cardioversion is another form of this procedure, whereby the electrical charge is applied by means of a catheter threaded through a vein leading to the heart.

Patients should not feel the charge from the electrical current because they are sedated. Each charge lasts only a second. A successful cardioversion may require several electrical charges to be given at incrementally larger energy levels. The entire procedure takes about a half hour.