How you prepare

By Mayo Clinic Staff

Cardioversion procedures are usually scheduled in advance, although if your symptoms are severe, you may need to have cardioversion in an emergency setting.

You generally can't eat or drink anything for 12 hours before the procedure. Your doctor will tell you whether you should take any of your regular medications before the procedure. If you do take medications before the procedure, sip only enough water to swallow your pills.

Before cardioversion, you may have a procedure called a transesophageal echocardiogram to check for blood clots in your heart, which can be dislodged by cardioversion, causing life-threatening complications. Your cardiologist will decide if you need a transesophageal echocardiogram before cardioversion.

In a transesophageal echocardiogram, your throat is numbed and a flexible tube (catheter) with a transducer attached is guided down your throat and into your esophagus, which connects your mouth to your stomach. From there, the transducer can obtain more-detailed images of your heart so that your doctor can check for blood clots.

If your doctor finds blood clots, your cardioversion procedure will be delayed for a few weeks while you take blood-thinning medications to reduce your risk of complications.

May. 17, 2014