An arrhythmia is a problem with the rate or rhythm of the heartbeat. It can cause the heart to beat too fast, too slow, or irregularly. If the heartbeat is too fast, it is called tachycardia; if it is too slow, it is called bradycardia. There are many types of arrhythmias, and most are harmless. […]

Atrial fibrillation (AF, or “A-Fib”) is the most common type of arrhythmia, or irregular heartbeat. Often mistaken for normal heart palpitations or written off as the result of aging, AF usually increases in duration and severity over time if untreated. AF affects 2 million Americans and is responsible for one in four strokes among people over 80.

Thanks to advances in wearable health-tracking devices, people can monitor their heart rhythms much easier now. Commercially available heart monitors may provide early detection of irregularities, but experts say the devices should be used in partnership with a doctor.