Effects of consistent atrial pacing and atrial rate stabilization - two pacing algorithms to suppress recurrent paroxysmal atrial fibrillation in brady-tachy syndrome

Background and method Recently, various dedicated atrial pacing algorithms have been proposed to prevent atrial fibrillation (AF). Consistent atrial pacing (CAP; an algorithm for automatic atrial overdrive) and atrial rate stabilization (ARS; an algorithm for preventing the 'short-long' sequences) were tested in 16 patients with brady-tachy syndrome and recurrent paroxysmal AF (greater than or equal to3 episodes per month). Results In the population as a whole, pacing with CAP was associated with a significant reduction in AF burden in comparison with DDDR pacing. With regard to the effects on AF burden, 11 patients (69%) were found to benefit significantly from CAP or ARS pacing algorithms (reduction > 50% in AF burden). In detail, seven patients were responders to both algorithms, two to CAP only and two to ARS only. Two patients exhibited a significant increase in AF burden with the ARS algorithm. With regard to the effects on number of mode switches per day, seven patients (44%) were found to benefit significantly from CAP or ARS pacing algorithms (reduction in mode switches per day > 50%). In detail, five patients were responders to both algorithms and two to ARS only. Two patients had a significant increase in the number of mode switches per day with both CAP and ARS algorithms. Conclusion The response to ARS and CAP algorithms is heterogeneous. In 31-69% of patients with brady-tachy syndrome a significant reduction in AF burden and/or mode switch episodes can be obtained with ARS and/or CAP algorithms; however, in a few patients an increase in AF episodes and/or AF burden may occur. (C) 2001 The European Society of Cardiology.