Your heart has a natural electrical system that ensures it beats at a normal rate. Electrical impulses begin in the sinus node (SA node) and travel through the atria and ventricles, prompting the heart to pump blood throughout the body. Issues with the SA node or the AV node (which regulates impulses between the atria and ventricles) or a blockage of the electrical signal—known as “heart block”—can lead to bradycardia.

A slow heartbeat may also indicate a congenital heart defect or damage to the heart tissue, which can be caused by heart disease, a heart attack, or the natural aging process. Myocarditis, which is inflammation of the heart tissue, can also cause bradycardia, and inflammatory conditions like lupus may contribute to this issue. Additionally, some medications may cause a slow heartbeat, and it can sometimes be associated with hypothyroidism or obstructive sleep apnea.