What is Sinus Node Dysfunction?
The sinus node (SA node) consists of a group of specialized cells within the right atrium and is the heart's natural pacemaker. Normally, the heart's electrical impulse starts in the SA node. This important structure allows the heart rate to increase or decrease in response to the body's activity level. Sinus node dysfunction (SND) can occur in patients with congenital heart disease (CHD), especially those who have had cardiac surgery which results in scarring within the right atrium.