Treatment for Atrial Fibrillation
In unstable patients with atrial fibrillation, those experiencing severe shortness of breath, chest pains, or lightheadedness due to low blood pressure, it may be necessary to "shock" the heart back into sinus rhythm.
Cardioversion is used to attempt to convert the patient with atrial fibrillation (AFib, AF) back into sinus rhythm by electrically shocking the heart. During this procedure, the patient is usually sedated or put to sleep through intravenous infusion of one of several new short-acting medications. Special pads or paddles are then applied to the chest and increasing energy levels of electrical charge are produced in an attempt to shock the heart back into sinus rhythm. Although the shocks can cause significant discomfort, most patients are asleep during the procedure and remember little, if anything, about the experience afterward.
Treatment for Atrial Fibrillation Complications
Some patients who are converted from atrial fibrillation to sinus rhythm, either by medicines or by shocking the heart, have a small risk that a clot has already formed in the left atrium. Once the heart is converted back into sinus rhythm, this clot may travel to the left ventricle and then be pumped to the brain, causing a stroke.
It is generally believed that patients at risk for this complication are those that have been in AFib, without being treated with blood-thinning agents, for more than two or three days or for some unknown duration. In these patients, two approaches are utilized. The first is to place the patient on the blood thinner warfarin (Coumadin®) for 3 to 4 weeks before attempting to convert the atrial fibrillation back to sinus rhythm. Treatment during this time prevents the formation of additional blood clots and allows the body to more or less dissolve any blood clot that may have formed in the left atrium. Many factors influence the decision to treat a patient with 3 to 4 weeks of blood-thinning therapy before attempting to convert the heart, or to perform a TEE and then attempt to convert the heart.
The second approach to treating an unstable patient is a procedure called transesophageal echo (TEE) During a TEE, a special microphone device is passed down the mouth into the esophagus, which is located directly behind the heart. Special sound waves are sent through this microphone-like device to image the heart and its chambers. The excellent quality of the pictures of the heart's chambers obtained by this process can be used to assess whether or not a clot has formed in the left atrium. If no clot is seen, an attempt is made to convert the heart back into sinus rhythm. Patients undergoing TEE are usually given an intravenously administered sedative to relax them during the procedure and have their throats sprayed with a numbing medication, making it easier to tolerate the procedure.