Sick sinus syndrome (SSS) – colloquially called sinus node syndrome – (synonyms: Bradycardia–tachycardia syndrome; Charcot-Weiss-Baker syndrome; sinus node disease; ICD-10 I49.5: sick sinus syndrome) is a cardiac arrhythmia that belongs to the group of stimulus-forming disorders.
Sick sinus syndrome includes the following functional disorders:
- Sinus bradycardia (< 60 heartbeats per minute).
- Intermittent SA block (sinuatrial block) or sinus arrest (sinus node arrest).
- Bradycardia-tachycardia syndrome bradycardic phases of the heartbeat (< 60 beats per minute) alternating with tachycardic phases (> 100 beats per minute); this is often associated with an inadequate rate rise under stress (chronotropic incompetence)
These dysfunctions are based in the aggregate on malfunctions of the sinus node (“natural pacemaker of the heart“).
Sex ratio: men and women are equally affected.
Frequency peak: the disease occurs predominantly after the age of 50. Sick sinus syndrome can also occur in children, especially if they have had surgery on the right atrium due to congenital vitiation (congenital heart defects).
Course and prognosis: In chronic sick sinus syndrome with symptomatic bradycardia (heartbeat < 60/minute; if vertigo (dizziness) and syncope (brief unconsciousness) occur, implantation of a pacemaker is required. Sick sinus syndrome is causally responsible for approximately 29% of all pacemaker implantations.
