To prevent paroxysmal and persistent atrial fibrillation, this algorithm adjusts the atrial pacing rate just above the intrinsic rate of the patient. The objective is to maintain a percentage of atrial pacing > 90%.

• the device searches P waves during 16 rolling cycles (only AS cycles will be used)
• if 2 P waves are sensed within these 16 cycles, the device increases the atrial pacing rate to overdrive intrinsic conduction
• after having paced at the AF Suppression rate for the programmed number of Overdrive Pacing cycles, the device steps down its rate until it senses an additional two P waves
• if two P waves are sensed, it resumes overdrive pacing
• if it does not sense two P waves, it resumes operation at the base rate setting, the rest rate setting or the sensor indicated rate
• two new sensed P waves will trigger a new overdrive at any moment
• the overdrive rate is limited by the Maximum AF Suppression® Rate