Atrial flutter is now known to be a “macro-reentrant” atrial tachycardia occurring in a counter-clockwise direction within the right atrium. The atrial rate is typically between 250 and 350 beats per minute. In general, the AV node conducts every other beat resulting in ventricular rates which are 50% of the atrial rate.
Higher grades of block are usually not stable and the rate may accelerate with exercise or other increases in autonomic tone. Most patients will therefore require definitive therapy for atrial flutter. Many patients with flutter can be treated with a radio-frequency ablation procedure which can permanently prevent future bouts of atrial flutter in many patients.