Atrial Fibrillation



Atrial fibrillation is an irregular heart rhythm where the top chambers of the heart (atria) quiver. Normally these chambers beat in sequence with the lower parts of the heart (ventricles). This quivering or fibrillating does not allow for complete emptying of the upper chambers. Without complete emptying the blood can pool and this increases the risk of blood clot formation. The blood clots can then break loose and travel into the brain, lungs and other parts of the body. The blood clot that travels to the brain can cause a stroke because it will block circulation to that part of the brain.


The biggest danger of atrial fibrillation is stroke. Atrial fibrillation is found in 2.2 million Americans. Atrial fibrillation is responsible for 140,000 strokes annually, which is about 25% of all strokes. If you have atrial fibrillation, you can greatly decrease your risk for stroke with appropriate treatment.


Some people may have atrial fibrillation and not know it. Others may start to feel tired and a little unwell, while others my feel acutely ill. Atrial fibrillation may cause the heart to beat very fast which can be life threatening and slowing down the heart is a important to prevent heart failure.


The goals of treating atrial fibrillation are to convert to a normal rhythm and to prevent clot formation. Converting to a normal rhythm is not always possible, so preventing the blood from clotting while remaining in atrial fibrillation, is an important part of therapy.


Medications can be used to slow down the heart rate, stop atrial fibrillation and to keep the blood from clotting. When medications are not successful, there are several different treatments to try to convert the rhythm. These include electrical cardioversion, radiofrequency ablation and/or surgery.


In electrical cardioversion, sedation is given, and then an electric shock is delivered to the heart to restore normal heart rhythm.


In radiofrequency ablation, a thin flexible catheter is inserted through a blood vessel and guided to the heart muscle. Sophisticated equipment is then used to determine the exact area of the heart that is causing the abnormal electrical responses that are causing the atrial fibrillation. Once identified, this tissue is then altered using radiofrequency energy to stop the abnormal stimulus which causes the atrial fibrillation.


Surgery can also be used to destroy the abnormal electrical pathways that cause atrial fibrillation. “Maze” is a surgical procedure where a heart surgeon makes multiple cuts into the atria in a Maze type pattern. The scars created from these cuts do not conduct electrical energy so the abnormal electrical impulses which caused atrial fibrillation do not spread through the atria. This helps prevent atrial fibrillation and restores a normal rhythm.


The most common place for clot formation in the atria is an area called the left atrial appendage. Anticoagulation medications can be given to prevent clot formation in this area. New procedures and devices such as the Watchman Device and the Lariat II are being used to close off this appendage and are showing success in preventing clot formation.


To prevent blood clot formation, anticoagulant and antiplatelet medications make the blood less prone to clotting. Warfarin (Coumadin) and Pradaxa (dabigatran) are the anticoagulants most often used. Aspirin and Plavix (clopidogrel) are the antiplatelet drug most often used. Antiplatelets medications are not as effective as anticoagulants in preventing stroke, but have a lower risk of bleeding complications. Long-term use of warfarin in patients with atrial fibrillation and other stroke risk factors can reduce stroke by 68 percent. A stroke caused by atrial fibrillation is often worse than other causes of stroke. It is therefore very important that patients with atrial fibrillation get treatment.


References and Further information on Atrial Fibrillation: UnderstandingRiskyConditions/When-the-Beat-is-Off—Atrial-Fibrillation_UCM_310782_Article.jsp