What is the role of bradycardia and pacing indication for the efficacy of preventive pacing?
In the present study, the response to preventive pacing algorithms was not different between patients with bradycardia and patients with AT as the only indication for pacing. This is in contrast to a subanalysis of the AFT study where improvement by the addition of dedicated algorithms on top of DDDR pacing at 70 bpm was more pronounced in patients without bradycardia [13]. Of note, in the present study patients with AT alone were paced in the atrium for 86% of the time which is unusual for patients without bradycardia. This atrial pacing percentage is in contrast to data from the PA3 study where DDDR pacing at 70 bpm in patients without bradycardia achieved atrial pacing for only 67% of the time [14]. Most likely, in the present study some of the patients had developed asymptomatic or slight sinus bradycardia due to antiarrhythmic drugs. Therefore, most of the antiarrhythmic potential of pacing may have already been achieved by DDD pacing at 70 bpm leaving little to gain by continuous
