Atrial Fibrillation - Causes - Causes

Changes to the heart’s tissue and to its electrical signals most often cause atrial fibrillation. To understand atrial fibrillation, it helps to know how the heart works. When the heart’s tissue or signaling is damaged, the regular pumping of the heart muscle becomes fast and irregular. Most often, damage to the heart is the result of other conditions such as high blood pressure and ischemic heart disease. Other factors can also raise your risk of atrial fibrillation.

Illustration of atrial fibrillation
Atrial fibrillation. This image shows the electrical system of the heart during atrial fibrillation. Normally, an electrical signal at the sinoatrial (SA) node in the upper right chamber of the heart causes the upper chambers to contract and pump blood into the lower chambers. The electrical signal travels down the heart and causes the lower chambers to contract. In atrial fibrillation, abnormal electrical signals in the upper chambers overwhelm the normal signal from the SA node and cause the upper chambers to beat irregularly. This image includes a graphical representation of the EKG (ECG) showing the electrical impulses illustrated within the heart. Medical Illustration Copyright © 2019 Nucleus Medical Media, All rights reserved.