Arrhythmia

Also known as Dysrhythmia

An arrhythmia is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slowly, or with an irregular rhythm. When a heart beats too fast, the condition is called tachycardia. When a heart beats too slowly, the condition is called bradycardia.

Arrhythmia is caused by changes in heart tissue and activity or in the electrical signals that control your heartbeat. These changes can be caused by damage from disease, injury, or genetics. Often there are no symptoms, but some people feel an irregular heartbeat. You may feel faint or dizzy or have difficulty breathing.

The most common test used to diagnose an arrhythmia is an electrocardiogram (EKG or ECG). Your doctor will run other tests as needed. She or he may recommend medicines, placement of a device that can correct an irregular heartbeat, or surgery to repair nerves that are overstimulating the heart. If arrhythmia is left untreated, the heart may not be able to pump enough blood to the body. This can damage the heart, the brain, or other organs.

Explore this Health Topic to learn more about arrhythmia, our role in research and clinical trials to improve health, and where to find more information.