Cardiac Arrhythmias

Also known as abnormal heart rhythm or dysrhythmia

A cardiac arrhythmia is when your heartbeat is too fast (tachycardia), too slow (bradycardia), or beats in an irregular rhythm due to a disruption of your heart’s normal electrical system. Many arrhythmias are harmless and cause only palpitations. Others are life-threatening, such as ventricular fibrillation, which can lead to sudden cardiac arrest.

Frequently Asked Questions

Key Terms

Page Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Heart, Lung, and Blood Institute. Arrhythmia.

  2. Pollack Ross A., Brown Siobhan P., Rea Thomas, et al. Impact of bystander automated external defibrillator use on survival and functional outcomes in shockable observed public cardiac arrests. Circulation. 2018;137(20):2104-2113. doi:10.1161/CIRCULATIONAHA.117.030700

  3. Cleveland Clinic. Pulse and heart rate. Updated November 18, 2018.

Additional Reading
  • National Heart, Lung, and Blood Institute. Arrhythmia.