Sick Sinus Syndrome
(SSS; Bradycardia-Tachycardia Syndrome; Sinus Node Dysfunction)
by Amy Scholten, MPH
Sick sinus syndrome is a group of symptoms due to faulty sinus node. The sinus node is a cluster of cells in the heart. These cells make the heart beat normally. When the sinus node does not work well, it can lead to:
Sick sinus syndrome usually gets worse. Over time, it can lead to serious heart problems.
The sinus node sets the pace of the heart. It creates and sends signals that make the heart beat in a regular pattern. The sinus node's function may be disrupted by:
Sick sinus syndrome is fairly rare. It is more common in older people. Other things that may raise the risk are:
At first, sick sinus syndrome may not have symptoms, or the symptoms may come and go.
When symptoms happen, they may be:
Sick sinus syndrome is often not found unless there are symptoms. The doctor will ask about symptoms and past health. A physical exam will be done. To diagnose the condition, heart tests may be done, such as:
For those with no symptoms, treatment may not be needed. Over time, sick sinus syndrome can raise the risk of atrial fibrillation, heart failure, heart attack, or stroke. As a result, the doctor will need to monitor heart health.
Treatment may be needed if uneven heart patterns disrupt blood flow through the heart. Options may be:
Underlying conditions may also need to be treated.
There are no guidelines to prevent sick sinus syndrome.
American Heart Association
Heart Rhythm Society
Canadian Heart Rhythm Society
Heart and Stroke Foundation of Canada
De Ponti R, Marazzato J, et al. Sick sinus syndrome. Card Electrophysiol Clin. 2018;10(2):183-195.
Sick sinus syndrome. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/sick-sinus-syndrome. Accessed September 13, 2021.
Sick sinus syndrome. Heart Rhythm Society website. Available at: https://upbeat.org/heart-rhythm-disorders/sick-sinus-syndrome#axzz3NOr35s6f. Accessed September 13, 2021.
Sinus node dysfunction. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/sinus-node-dysfunction. Accessed September 13, 2021.
Last reviewed July 2021 by EBSCO Medical Review Board Nicole Meregian, PA
Last Updated: 9/13/2021