What is it?

Cardioversion is a brief procedure where an electrical shock is delivered to the heart to convert an abnormal heart rhythm back to a normal rhythm.

How does it work?

Cardioversion can be "chemical" or "electrical". Chemical cardioversion refers to the use of antiarrhythmia medications to restore the heart's normal rhythm. Antiarrhythmia medications work by modifying the heart's electrical properties to reduce the frequency of abnormal heart rhythms and to help restore a normal rhythm.

Electrical cardioversion is a procedure whereby a perfectly timed electrical shock is delivered through the chest wall to the heart through special electrodes or paddles that are applied to the skin of the chest and back to disrupt the abnormal electrical circuit(s) in the heart and to restore a normal heart beat. This split second interruption of the abnormal beat allows the heart's electrical system to regain control and restore a normal heartbeat.

Reasons for Cardioversion

Most elective or "non-emergency" cardioversions are performed to treat atrial fibrillation. Cardioversion is also used in emergency situations to correct a rapid abnormal rhythm associated with faintness, low blood pressure, chest pain, difficulty breathing, or loss of consciousness.

What to expect

Cardioversion is a safe and effective treatment to restore the heart rhythm back to normal.

Chemical cardioversion may be done as an outpatient or with oral medication or intravenously at a hospital or oral antiarrhythmia medication so the heart rhythm can be observed.

An electrical cardioversion is usually performed in a hospital’s electrophysiology laboratory. A cardiologist, a nurse and/or an anesthesiologist are present to monitor breathing, blood pressure and heart rhythm. Since the shock can be painful, an anesthesiologist or specially trained nurse, administers sedation intravenously. Once the patient is asleep, the doctor charges the defibrillator to a specified energy level and then delivers the shock by pressing a button on the defibrillator.

Rarely, minor chest discomfort or skin redness can occur at the site of the cardioversion pads where the electrical energy was delivered. Patients typically awake quickly without any recollection of the shocks. Most patients are able to go home an hour or so after the procedure but are unable to drive after receiving sedation medicine.

St. Luke's Heart & Vascular