* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Atrial Fibrillation
Remote ischemic conditioning wikipedia , lookup
Management of acute coronary syndrome wikipedia , lookup
Mitral insufficiency wikipedia , lookup
Cardiac contractility modulation wikipedia , lookup
Rheumatic fever wikipedia , lookup
Coronary artery disease wikipedia , lookup
Heart failure wikipedia , lookup
Antihypertensive drug wikipedia , lookup
Quantium Medical Cardiac Output wikipedia , lookup
Myocardial infarction wikipedia , lookup
Cardiac surgery wikipedia , lookup
Jatene procedure wikipedia , lookup
Electrocardiography wikipedia , lookup
Atrial septal defect wikipedia , lookup
Lutembacher's syndrome wikipedia , lookup
Dextro-Transposition of the great arteries wikipedia , lookup
JAMA PATIENT PAGE | Cardiology Atrial Fibrillation Atrial fibrillation is a common arrhythmia (abnormal heart rhythm). The heart has 4 chambers: the right and left atria (upper chambers) and the right and left ventricles (lower chambers). A normal heartbeat begins in the right atrium. The sinoatrial (SA) node is a collection of specialized cells that initiate an electrical signal that travels through the heart muscle. This signal causes the atria to contract, which pumps blood from the atria into the ventricles. The signal travels through the atrioventricular (AV) node and into the muscle around the ventricles. When the ventricles contract, blood is pumped to the lungs and the rest of the body. Heart rate is the number of times your heart beats in 1 minute. Heart rhythm is the regularity of your heartbeat. In a normal rhythm, heartbeats are evenly spaced. In atrial fibrillation, the electrical signal that travels through the heart is uncoordinated. This disorganized electrical signal starts at a site other than the SA node and leads to a rapid and irregular heartbeat. During episodes of atrial fibrillation, blood is not pumped through the heart efficiently. Episodes may be brief or prolonged. Normal heart rhythm Atrial fibrillation Electrical activity starts in the SA node. The atria contract, and blood empties into the ventricles. Right atrium SA node AV node Electrical activity in the atria is disorganized. The atria quiver, and blood may pool and form clots. Left atrium BLOOD FLOW Right ventricle Clot Electrical signal Left ventricle Normal rhythm Atrial fibrillation rhythm Causes of Atrial Fibrillation Diseases that affect the heart are common causes of atrial fibrillation. These include heart failure, heart valve disease, high blood pressure, and heart attack. Other causes include obesity, chronic obstructive pulmonary disease, an abnormal heart structure, hyperthyroidism, and alcohol intoxication. Symptoms Some people with atrial fibrillation have symptoms such as palpitations (a fluttering sensation in the chest), shortness of breath, chest pain, dizziness, and fatigue. Other people do not have any symptoms and might not know they have atrial fibrillation. A doctor might identify an abnormal heart rhythm during a physical examination. Atrial fibrillation may also be found on an electrocardiogram that is performed for another reason. To help the heart maintain a regular rhythm, a doctor might prescribe an antiarrhythmic medication. A procedure called cardioversion is the use of an electrical shock (or, less commonly, a drug) to restore a normal rhythm. Catheter ablation involves using small electrodes to scar the heart tissue that generates abnormal electrical signals. If you have atrial fibrillation, you are at increased risk of stroke. A rapid, irregular heartbeat can cause blood to pool in the atria and a blood clot to develop. Many patients with atrial fibrillation are prescribed an anticoagulant (a medicine that helps prevent blood clots). Anticoagulation is especially important if you have atrial fibrillation and you are a woman, are aged 65 years or older, or have a history of congestive heart failure, high blood pressure, stroke or transient ischemic attack, vascular disease, or diabetes. Treatment Treatment approaches are different for different people. A doctor will consider your medical history and your symptoms before recommending a treatment plan. Goals of treatment include maintaining a normal heart rate and rhythm and preventing stroke. For many patients, medications that control heart rate can help maintain a normal heart rate by slowing the electrical signal as it travels through the AV node. For some patients, the best rate-control treatment option might be ablation (destruction) of the AV node and placement of a pacemaker. Author: Amy E. Thompson, MD Sources: National Heart, Lung, and Blood Institute, National Institutes of Health Marchlinski F. The tachyarrhythmias. In: Longo DL, Fauci AS, Kasper DL, et al, eds. Harrison’s Principles of Internal Medicine. 18th ed. New York, NY: McGrawHill; 2012:1881-1885. 1070 FOR MORE INFORMATION National Heart, Lung, and Blood Institute www.nhlbi.nih.gov/health/health-topics/topics/af To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish. The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776. JAMA March 10, 2015 Volume 313, Number 10 (Reprinted) Copyright 2015 American Medical Association. All rights reserved. Downloaded From: http://jamanetwork.com/ on 06/17/2017 jama.com