Rhythm control methods include electrical and chemical cardioversion:

• Electrical cardioversion involves the restoration of normal heart rhythm through the application of a DC electrical shock.
• Chemical cardioversion is performed with drugs, such as amiodarone, dronedarone, procainamide, ibutilide, propafenone or flecainide.

The main risk of cardioversion is systemic embolization of a thrombus (blood clot) from the previously fibrillating left atrium. Cardioversion should not be performed without adequate anticoagulation in patients with more than 48 hours of atrial fibrillation. Cardioversion may be performed in instances of AF lasting more than 48 hours if a transesophogeal echocardiogram (TEE) demonstrates no evidence of clot within the heart.

Whichever method of cardioversion is used, approximately 50% of patient relapse within one year, although the continued daily use of oral antiarrhythmic drugs may extend this period. The key risk factor for relapse is duration of AF, although other risk factors that have been identified include the presence of structural heart disease, and increasing age. [edit]Maintenance of sinus rhythm

The mainstay of maintaining sinus rhythm is the use of antiarrhythmic agents. Recently, other approaches have been developed that promise to decrease or eliminate the need for antiarrhythmic agents. The anti-arrhythmic medications often used in either pharmacological cardioversion or in the prevention of relapse to AF alter the flux of ions in heart tissue, making them less excitable, setting the stage for spontaneous and durable cardioversion. These medications are often used in concert with electrical cardioversion.

These medications help return the heart to its normal sinus rhythm or maintain normal sinus rhythm. There are several types of rhythm control medications, including: Quinidex (quinidine); Pronestyl (procainamide); Norpace (disopyramine); Tambocor (flecainide); Rythmol (propafenone); Betapace (sotalol); Tikosyn (dofetilide) and Cordarone (amiodarone). Some of these drugs are not available in the market these days. The last five drugs outlined in red are the most frequently used.

Patients may have to stay in the hospital for up to three days when starting some of these medications (sotalol and dofetalide) so that the heart rhythm and response to the medication can be carefully monitored. These medications are effective 30 to 60 percent of the time, but may lose their effectiveness over time. You may need to try several medications so your doctor can find the best one for you.

Some rhythm control medications may actually cause more arrhythmias, so it is important to discuss your symptoms and any changes in your condition with your doctor.

It is important to know more about the drugs you are on for your heart rhythm condition:

• the names of your medications
• what they are for
• how often and at what times to take them
• Make sure they are not interacting with the other drugs that you are taking (most of the pharmacies keep track of this information in the United States)