Atrial Fibrillation Frequently Asked Questions
What is Atrial Fibrillation?
Atrial fibrillation (AF) is a heart rhythm disorder (arrhythmia), usually involving a rapid heart rate, in which the upper heart chambers (atria) are stimulated to contract in a very disorganized and abnormal manner. This abnormal heart rhythm increases the likelihood that blood will pool and/or clots will form, which makes AF a leading cause of stroke.Prevalence
More than 3.5 million Americans, both men and women, have AF. Its prevalence increases with age and varies from 1 case out of 200 persons for people younger than 60 years, to almost 9 cases out of 100 persons for people over 80 years. AF accounts for one-third of hospital admissions for cardiac rhythm disturbances, and the rate of admissions for atrial fibrillation has risen in recent years.
The most serious problem related to AF occurs when the ineffective pumping action of the atria allows blood clots to form within the atria. If these blood clots break off and get into the bloodstream, they can cause a stroke. People with AF are 2-7 times more likely to suffer a stroke than the general population.
AF with a persistent rapid rate can cause a form of heart failure called tachycardia induced cardiomyopathy, which can significantly increase mortality and morbidity. Research suggests the added burden that inefficient atrial pumping puts on the ventricles also may contribute over time to heart failure. Stress, smoking and heavy drinking, obesity and a range of illnesses also raise the risks of developing the condition and the likelihood that it will be more difficult to treat.
Common symptoms include palpitations and heart pounding, as well as or other effects that may not seem related to the heart such as lightheadedness, fainting, headaches, shortness of breath, weariness or exercise intolerance. AF occasionally produces angina and chest pain due to lack of blood in the heart muscle, as well as congestive symptoms such as shortness of breath or edema. Some people with AF, however, may not feel any symptoms.Back to top
What causes Atrial fibrillation?
In atrial fibrillation, arrhythmias (irregular heart beats) are caused by a disruption of the normal functioning of the electrical conduction system of the heart. The electrical impulses that are normally generated by the sinoatrialnode -- the impulse generating (pacemaker) tissue located in the right atrium -- are replaced by disorganized activity, leading to irregular conduction of impulses to the ventricles that generate the heartbeat. This results in ineffective and uncoordinated atria contractions, which lead to an irregular (and usually fast) pulse.
Other causes include a number of heart and lung disorders, including coronary artery disease, rheumatic heart disease, mitral valve disorders, pericarditis, and others. Recent research suggests susceptibility to AF may be inherited in some cases. It also may be caused by factors unrelated to the heart such as medications, metabolic diseases, substances in the environment, diet and stress.Back to top
How do we diagnose AFib?
The fleeting nature of arrhythmias makes it difficult to actually capture an event during any single test. Sometimes it¿s necessary to monitor the heart over time. Sometimes specialists provoke abnormal rhythms in a safe environment to evaluate and diagnose a problem. Electrophysiologists conduct special tests to determine if nonspecific symptoms are related to problems in the heart's electrical conduction system or other types of heart disease.
The most commonly used diagnostic tests include:
- Electrocardiogram (ECG/EKG)
- Electrophysiology Study
- Holter Monitor
- Event Recorder
- Tilt Table Test