Relationship Between Selected Overdrive Parameters and the Therapeutic Outcome and Tolerance of Atrial Overdrive Pacing

Abstract

There is a paucity of information on the influence of selected overdrive parameters on the clinical efficacy and tolerance of atrial overdrive algorithms to suppress atrial tachyarrhythmias. Data from a completed clinical trial investigating a new DDD+ overdrive algorithm implemented in a permanent pacemaker were analyzed. One-hundred patients with standard pacing indications and atrial tachyarrhythmias were enrolled and followed for 6 months in DDD and 6 months in DDD+ mode in a randomized, crossover fashion. The overdrive step size was programmed at the discretion of the investigators between 4 and 12 beats/min, overdrive plateau length between 10 and 32 beats, and maximum overdrive rate between 100 and 160 beats/min. The effects of DDD+ versus DDD mode on burden and incidence of atrial tachyarrhythmias stored in the mode switch memory were examined as a function of the programmed overdrive parameters. An overdrive step size between 7 and 12 beats/min, and higher a maximum overdrive rate between 121 and 160 beats/min were slightly more effective than lower programmed values, though > 500 randomized, crossover observations would have been necessary to verify statistical significance. Overdrive pacing related symptoms mandated early manual deactivation of overdrive pacing in 4.7% of 85 evaluated patients. Overdrive was disabled without testing tolerability of less aggressive overdrive values. There was no link between patient symptoms and programmed overdrive step size or overdrive plateau length values.

Advances in Cardiac Pacing: Arrhythmia Prediction, Prevention and Control Strategies

“…Implantable pacemakers have been a breakthrough in preventing atrial arrhythmias by using specific atrial pacing algorithms ( Dimmer et al, 2003 ). Various studies have been done in the past which have shown that majority of the paroxysmal AF episodes are initiated by bradycardias, premature atrial complexes (PAC) or immediate reinitiation of AF, and multiple pacing modalities have been developed to prevent AF recurrences ( Hoffmann et al, 2000 ; Attuel et al, 2003 ; Yang et al, 2003 ). These algorithms primarily rely on the classification of atrial events by the pacemakers and work either by responding to triggers or by continuous overdrive atrial pacing.…”