Key Points

• Cardioversion is a procedure used to restore a fast or irregular heartbeat (an arrhythmia) to a normal rhythm.
• Cardioversion is done two ways: using an electrical procedure or using medicines. This article discusses electrical cardioversion. For this procedure, low-energy shocks are given to your heart to trigger a normal rhythm.
• Cardioversion isn't the same as defibrillation. Defibrillation gives high-energy shocks to the heart. It's used to restore normal heartbeats during life-threatening situations, such as cardiac arrest.
• You may need cardioversion if you have an arrhythmia that's causing troublesome symptoms. These symptoms may include dizziness, shortness of breath, extreme fatigue (tiredness), and chest discomfort.
• Atrial fibrillation is the most common type of arrhythmia treated with cardioversion.
• You may need cardioversion on an emergency basis if your symptoms are severe. However, you usually schedule this procedure in advance.
• You're at greater risk for dangerous blood clots during and after a cardioversion. This is because the procedure can dislodge blood clots that may have formed due to an arrhythmia. Your doctor may prescribe medicine both before and after the procedure to prevent these blood clots from causing complications, such as stroke.
• Before a cardioversion, you're given medicine to make you sleep through the procedure. While you're asleep, a cardiologist will give one or more low-energy electrical shocks to your heart to trigger a normal heartbeat. You won't feel any pain from the shocks due to the medicine used to make you sleep.
• Cardioversion takes just a few minutes. However, you will likely be in the hospital for a few hours due to the prep time and monitoring after the procedure.
• You will be watched closely for an hour or so after the procedure for any signs of complications. You may feel drowsy for several hours after cardioversion because of the medicine used to make you sleep. You should arrange for someone to drive you home after the procedure.
• Cardioversion has some risks. It can worsen arrhythmias. Rarely the procedure can cause stroke or other complications due to blood clots in the heart traveling to other organs or tissues. However, serious complications are rare.
• Cardioversion successfully restores normal heart rhythms in more than 75 percent of people who have the procedure.