An arrhythmia (ay-RITH-mee-uh) is an abnormal heart rhythm usually caused by an electrical "short circuit" in the heart.
The heart normally beats in a consistent pattern, but an arrhythmia can make it beat too slowly, too quickly, or irregularly. This can cause the heart muscle's pumping function to work erratically, which can lead to a variety of symptoms, including fatigue, dizziness, and chest pain.
Arrhythmias can be temporary or permanent. They can be caused by several things, but also can occur for no apparent reason. Congenital (present at birth) arrhythmias sometimes are due to a birth defect of the heart, but some happen even when the heart has formed normally.
Many arrhythmias don't require treatment; however, some can pose a health problem and need to be evaluated and treated by a doctor.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
