Termination of symptoms in the sick sinus syndrome by atrial fibrillation.

A female patient with symptomatic sick sinus syndrome (SSS) had a permanent pacemaker implanted. She later developed chronic atrial fibrillation with an adequate ventricular rate. When the pulse generator failed she was found to be clinically asymptomatic. This patient had never adjusted emotionally to her pacemaker and, since she was asymptomatic and in a stable rhythm, the failed pacemaker was not replaced. Possibly, thought should be given to the discontinuance of pacing for the SSS when, in the presence of adequate A-V conduction, stable atrial fibrillation develops.