Single-loop biatrial tachycardia mimicking typical atrial flutter in a patient without a history of cardiac surgery or ablation

Biatrial tachycardia (BiAT) is a rare form of macro-reentrant atrial tachycardia involving both the right and left atria. It often occurs in patients with a history of cardiac surgery or catheter ablation, where surgical incisions or ablation lesions serve as arrhythmogenic substrates.1,2 Here, we report a case of a single-loop BiAT that mimicked typical atrial flutter (AFL) without a previous history of cardiac surgery or ablation.