Unexpected recurrence of sinus rhythm in chronic atrial fibrillation due to sick sinus disease.

A 60-years old patient with symptomatic sick sinus disease was implanted a dual-chamber pacemaker that did well during the following 13 years. Thereafter, the pacemaker had to be explanted because of a systemic infection, with the patient in constant chronic atrial fibrillation in the meantime. After another asymptomatic year, 6 arrhythmogenic syncopes occurred, apparently due to pre-automatic pauses prior to spontaneous conversions to sinus rhythm. Subsequently, the patient was implanted a VVI pacemaker, whereupon he did well henceforth. This case demonstrates the possibility of recurrence of sinus rhythm even after long-standing chronic atrial fibrillation.