The prevalence of sinus rhythm in patients with "permanent" atrial fibrillation

Background The term "permanent" atrial fibrillation (AF) is generally used to describe the rhythm status of patients for whom cardioversion has failed or attempts to restore normal sinus rhythm (NSR) have ceased. However, the rhythm status of such patients is typically assessed by symptoms or intermittent monitoring, and therefore categorization may be imprecise. Methods We evaluated the presence of NSR among patients who were identified by their physicians as having permanent AF and who underwent prior insertion of a cardiac rhythm management device in the OMNI study. Patients with a dual- or triple-chamber device (pacemaker, implantable cardiac defibrillator, or cardiac resynchronization therapy) and ≥30 days of device data were studied. We tabulated the percentage of follow-up days spent entirely in NSR, entirely in AF, or in both NSR and AF. Results A total of 69 patients met inclusion criteria and were followed for 767 ± 479 days. More than 73% of patients experienced ≥1 entire day in NSR. On average, 38.2% of days were spent entirely in NSR, 11.8% of days were spent in a combination of NSR and AF, and only 50.0% of days were spent entirely in AF. The median daily AF burden during follow-up was 14.6 [1.1-23.7] hours/day. Conclusions NSR is common in many device patients thought to have permanent AF, suggesting that continuous arrhythmia monitoring could be useful in identifying permanent AF patients who may benefit from renewed rhythm control efforts. Alternatively, some permanent AF patients undergoing atrioventricular nodal ablation may benefit from dual-chamber devices due to likely periods of NSR.