Overview

What Is Arrhythmia?

Your heart beats approximately 100,000 times every day—about 35 million times a year, delivering oxygen-rich blood to your body. Each heartbeat begins with an electrical impulse within your heart’s own electrical network, called the conduction system.

The conduction system consists of a group of specialized cells within the wall of your heart. Each heartbeat starts as an electrical impulse in the atria (upper chambers of the heart) that travels down to the ventricles (lower chambers of the heart).

In a healthy heart, electrical impulses occur at regular intervals. When something is wrong with your heart’s conduction system, the electrical impulses of your heart are not regular, so your heart does not beat as expected. These irregular heartbeats result in a heart rhythm disorder, or arrhythmia, that include heartbeats that are too fast (tachycardia), too slow (bradycardia), and/or irregular (extra or skipped beats).  

Arrhythmias can range from harmless to life-threatening. Minor variations in your heart rate can be normal. However, extreme and prolonged changes in heart rate are abnormal and can cause symptoms. The normal heart rate is usually between 60 and 100 beats per minute.