A peculiar form of focal atrial tachycardia mimicking atypical atrial flutter

A 55-year-old man was referred because of congestive heart failure and atri al flutter. A 12-lead electrocardiogram (ECG) showed positive P waves in le ads II, III, and aV(F) with a continuously undulating pattern that lacked a n isoelectric baseline. Tachycardia was diagnosed as atypical atrial flutte r based on classical criteria. An electrophysiological study and catheter a blation using an electroanatomical system revealed the mechanism of the tac hycardia to be focal atrial tachycardia originating from the left atrial ro of. This case indicates that focal atrial tachycardia may present as atypic al atrial flutter on the surface EGG.