Atrial fibrillation, the most common type of arrhythmia, occurs when the atria beats at up to 600 times per minute, causing the chambers to quiver instead of contract effectively. A normal atria beats 60-80 times per minute.
- There are three main types of atrial fibrillation: episodic, lasting from a few minutes to a few hours; persistent, lasting for days or weeks; or permanent.
- In atrial fibrillation, blood does not fully pass through the atria. Instead, some blood pools in your heart, which can sometimes enable a blood clot to form and possibly enter your bloodstream. This clot can travel and block the blood flow in your brain, causing a stroke. Atrial fibrillation can also lead to cardiomyopathy (enlargement of the heart), which eventually weakens your heart.
- The risk of atrial fibrillation is higher in people older than age 60, in men, and in people who have diabetes, high blood pressure, congestive heart failure or lung disease.
Atrial fibrillation FAQs
1. What are the symptoms of atrial fibrillation?
Although atrial fibrillation may not always cause symptoms, some symptoms include: palpitations, dizziness or feeling lightheaded, fainting (syncope), weakness, fatigue, dyspnea, and/or angina.
2. What causes atrial fibrillation?
Atrial fibrillation is most commonly caused by cardiovascular problems, such as: hypertension (high blood pressure), valvular disorders or disease, ventricular hypertrophy (enlargement of the heart's lower chambers), cardiomyopathy, atherosclerosis ("hardening of the arteries"), sick sinus syndrome, and/or pulmonary embolism.
3. How is atrial fibrillation diagnosed?
To help diagnose atrial fibrillation, Boston Medical Center's electrophysiologists use one or more of the following tests:
- Electrocardiogram. This device tracks and graphs heart rhythm using electrical signals from the heart.
- Trans-esophageal echocardiogram. This test produces real-time moving images on a monitor, taken from inside the esophagus and stomach.
- Holter monitor. This device monitors and records the heart rhythm continuously for 24-48 hours.
- Event recorder. An event recorder is activated during episodes of fibrillation and records the heart rhythm at that time.
4. How is atrial fibrillation treated?
The goal of treating atrial fibrillation is to slow the heart rate and prevent blood clots from forming, and to correct the heart rhythm. A doctor may recommend:
Medical treatments (medications)
- Rate control and anticoagulation. These medications help return the heart to its normal rate and prevent clots from forming. The doctor may prescribe rate-control medications, such as beta-blockers, calcium channel blockers, and digitalis, as well as anticoagulation medication, such as Coumadin.
- Anti-arrhythmic drug therapy. Anti-arrhythmic drugs restore normal heart rhythm by slowing the movement of the impulse through heart tissue or lengthening the shortest time possible between two connective beats.
Interventional treatments (procedures)
- Cardioversion. This procedure restores normal heart rhythm using a brief electric shock through the chest.
- AV nodal ablation and permanent pacemaker implantation. This treatment destroys the atrioventricular (AV) node, a part of the heart's electrical system through which electrical signals pass from the atria to the ventricles. The electrophysiologist destroys the AV node with a burst of energy, stopping the signals from reaching the ventricles. Following the ablation, your doctor implants a pacemaker to control your heart rhythm.
- Pulmonary vein isolation. This procedure uses a burst of energy to destroy the tissue that produces the electrical signals that cause the arrhythmia and create scar tissue around the pulmonary vein, which blocks electrical signals from entering the atrium.