What is the role of the sick sinus syndrome in the pathophysiology of sinus bradycardia?

Updated: Dec 27, 2017
  • Author: Mark W Livingston, MD; Chief Editor: Erik D Schraga, MD  more...
  • Print
Answer

Sinus bradycardia may also be caused by the sick sinus syndrome, [3] which involves a dysfunction in the ability of the sinus node to generate or transmit an action potential to the atria. Sick sinus syndrome includes a variety of disorders and pathologic processes that are grouped within one loosely defined clinical syndrome. The syndrome includes signs and symptoms related to cerebral hypoperfusion in association with sinus bradycardia, sinus arrest, sinoatrial (SA) block, carotid hypersensitivity, or alternating episodes of bradycardia and tachycardia.

Sick sinus syndrome most commonly occurs in elderly patients with concomitant cardiovascular disease and follows an unpredictable course. Some studies have shown that these patients have a functional decrease in the number of nodal cells, while others have demonstrated the presence of antinodal antibodies. Although these and other developments are beginning to focus our understanding of this syndrome, most cases remain idiopathic.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!