FACTBOX: Cheney condition makes heart flutter

(Reuters) - Vice President Dick Cheney was diagnosed with atrial fibrillation on Monday -- a common but serious condition that causes the heart's upper chambers to flutter.

The heart's two small upper chambers quiver instead of beating effectively and blood is not pumped completely out, which can cause it to pool and clot.

Here are some facts about atrial fibrillation:

LINK TO STROKE

-- Atrial fibrillation is one of the most common types of heart arrhythmia and is considered benign. However, people with it are two to seven times more likely to suffer a stroke, which happens when a blood clot leaves the heart and becomes lodged in an artery in the brain or leading to the brain.

RISK FACTORS

-- The risk of developing atrial fibrillation increases with age. It is often associated with valvular heart disease, high blood pressure, clogged arteries and many other types of heart disorders. Three to 5 percent of people over 65 have atrial fibrillation. In the United States, 2.2 million Americans suffer from the condition.

SYMPTOMS

-- Atrial fibrillation symptoms include heart palpitations, dizziness, fainting, fatigue, shortness of breath, chest tightness and pain. Sometimes there are no symptoms at all.

TREATMENT

-- It is important to treat AF in order to prevent stroke. Many heart drugs can help, including drugs designed to slow the rapid heart rate associated with atrial fibrillation and blood thinners or anticoagulants that make a clot less likely to form.

Pacemakers can also be implanted. Cheney already has an implantable cardioverter defibrillator in his chest that is supposed to shock his heart back to a normal rhythm if a severe problem occurs.

(Reporting by Maggie Fox in Washington; Editing by Will Dunham and Bill Trott)