The purpose of the study was to confirm the AT500 intervention pacing effectiveness data previously seen in the ASPECT clinical trial and to gather additional data to understand the effectiveness of the intervention pacing features. Specifically, the goal of the trial is to demonstrate a reduction in frequency in symptomatic atrial tachycardia/atrial fibrillation recurrence with the intervention pacing features in patients with a pacing indication and a history of atrial tachyarrhythmias with atrial pacing leads located in the region of Bachmann's Bundle.