Macro-reentrant Single-loop Biatrial Flutter Appearing as Typical Atrial Flutter: Case Study and Review.

Biatrial flutter is a rare form of macro-reentrant atrial tachycardia that involves both the right and left atria. Single-loop biatrial flutter is typically associated with scarring of the septum from prior ablation or surgery and is generally made up of two interatrial connections-that is, the coronary sinus and Bachmann's bundle. Entrainment and high-density mapping allow for rapid diagnosis and development of a treatment strategy. Ablation planning should also take into consideration the preservation of interatrial conduction. We herein discuss a case of single-loop biatrial flutter presenting as a typical atrial flutter and review the differential diagnosis and physiology of the arrhythmia.