Why Dick Cheney's Heart Skipped a Beat

Vice President Dick Cheney was admitted to and released from the hospital Wednesday because he was "experiencing a recurrence of atrial fibrillation, an abnormal rhythm involving the upper chambers of the heart," his spokeswoman Megan Mitchell said.

Atrial fibrillation (AF), the most common affliction of the heart, affects more than 2 million Americans.

All hearts flutter from time to time. These arrhythmias are generally harmless and may have no discernable cause at all. But if it happens frequently or is accompanied by other symptoms (like shortness of breath), the sight of your sweetie might not be to blame.

Those with the disorder have hearts whose upper chambers beat irregularly and too rapidly. AF alone is typically not life-threatening, but it can cause blood clots and is linked to one-third of all strokes in those over 65. It arises not from swooning or sneezing, but usually from infections or some other heart disease.

There may also be a link between AF and alcohol consumption, excessive caffeine, stress and drug use. In some cases, a heritable genetic defect causes AF.

Cheney, who has had four heart attacks dating back to age 37, was given electric-shock treatment to get his heart back on track.