In a brief report published five years ago in The Journal, Ferrer1 grouped together a variety of conditions attributable to a failing sinoatrial node under the name of the "sick sinus syndrome." Characteristic of the syndrome are one or more of the following six manifestations: severe, persistent sinus bradycardia, particularly under stress when tachycardia would be a more appropriate response; sinus arrest with replacement by atrial or junctional rhythms; sinus arrest without rescue by other rhythms and a consequent cardiac standstill; chronic atrial fibrillation, with a slow ventricular rate due to an associated atrioventricular block; failure of cardioversion to restore sinus rhythm in atrial fibrillation; and episodes of sinoatrial block not related to therapy.
In a more recent review,2 the same author restates the six cardinal features of the sick sinus syndrome, enlarging on its cause, pathophysiologic characteristics, diagnosis, natural history, prognosis, and treatment. As distinct from transient
The Sick Sinus. JAMA. 1973;225(6):632. doi:10.1001/jama.1973.03220330044015