You usually can't have any food or drinks for about 12 hours before having cardioversion (as your doctor advises).
You're at higher risk for dangerous blood clots during and after a cardioversion. The procedure can dislodge blood clots that have formed as the result of an arrhythmia.
Your doctor may prescribe anticlotting medicine to prevent dangerous clots. He or she may recommend that you take this medicine for several weeks before and after the cardioversion procedure.
To find out whether you need anticlotting medicine, you might have transesophageal echocardiography (TEE) before the cardioversion. TEE is a special type of ultrasound. An ultrasound is a test that uses sound waves to look at the organs and structures in the body.
TEE involves a flexible tube with a device at its tip that sends sound waves. Your doctor will guide the tube down your throat and into your esophagus (the passage leading from your mouth to your stomach). You’ll be given medicine to make you sleep during the procedure.
Your doctor will place the tube close to your heart, and the sound waves will create pictures of your heart. Your doctor will look at these pictures to see whether you have any blood clots.
The TEE will be done at the same time as the cardioversion or just before the procedure. If your doctor finds blood clots, he or she may delay your cardioversion for a few weeks. During this time, you'll take anticlotting medicine.
Even if no blood clots are found, your doctor may prescribe anticlotting medicine during and after the cardioversion to prevent dangerous blood clots from forming.
Before the cardioversion procedure, you’ll be given medicine to make you sleep. This medicine can affect your awareness when you wake up. So, you'll need to arrange for someone to drive you home after the procedure.