The case of a patient with frequent episodes of atrial fibrillation that organizes into atrial flutter following implantation of a dual chamber, rate adaptive pacemaker is reported. The atrial flutter was effectively pace-terminated following activation of the atrial antitachycardia pacing therapies in the pacemaker. This resulted in a decrease in atrial fibrillation burden over time. The present case also illustrates the value of diagnostic data retrieved from pacemakers for monitoring atrial fibrillation frequency over time and evaluating the efficacy of pacing and drug therapy.