If a patient's atrial fibrillation doesn't respond to medication, the doctor may recommend a more aggressive approach. Even if he isn't at high risk for stroke, with prolonged AF, the atria may begin to enlarge. Enlarged atria pump blood even less efficiently, which can lead to congestive heart failure.

• Electrical cardioversion may be recommended to reset the heart to a normal rhythm. This noninvasive procedure is performed in a hospital, and he'll be given sedation through an IV. Once he falls asleep, two electrode pads or paddles will be applied to his skin: one near the breastbone, and the other on the lower left chest or back. A burst of electrical current is sent through them, shocking the heart. If the procedure is successful, his heart rhythm will be restored to normal -- at least temporarily -- and he'll probably be able to return home that day and resume normal activities in a day or two.

• Radiofrequency catheter ablation is another procedure that may help. The person you're caring for will be given a local anesthetic to numb the points where the catheter is inserted (usually the groin, neck, or elbow). The cardiologist will thread thin flexible tubes (catheters) through one or more blood vessels until they reach the heart. Once the cardiologist determines exactly which heart cells are causing the abnormal rhythm, she'll deliver a burst of radiofrequency energy to destroy those cells. He should be able to go home that day and will probably be able to resume normal activities in a few days.

• An implantable pacemaker to keep his heart beating at a normal rate may help if the AF occurs only when the person's heart rate is very slow. The procedure takes place in a hospital, with light sedation and local anesthetic. The cardiologist will implant the pacemaker wires directly into his heart, while the battery and other components are inserted just under the skin of the chest or abdomen. The procedure takes about an hour, but he'll spend the night in the hospital. His pacemaker will need to be checked in four to eight weeks.

• An implantable atrial defibrillator may help in rare cases. Like an electrical cardioversion, this device delivers an electrical shock to the heart to restore its rhythm to normal. Implantable defibrillators aren't typically used for AF, but it might be necessary if the person you're caring for also has a ventricular arrhythmia.

• Surgery may be needed if other treatments fail to correct the patient's AF or if he has one or more strokes. Unlike cardioversion or catheter ablation, surgery requires six to eight weeks of recovery. The surgeon may perform a maze procedure (the name refers to the complex series of incisions required). If the person you're caring for is undergoing surgery for another problem, the surgeon may perform a modified maze procedure instead. The Cleveland Clinic's website offers detailed descriptions of these surgical techniques.