Atrial flutter

Atrial flutter.
(A) Lead V1 and lead II ECG tracings show AFL with a moderate ventricular response and variable AV conduction, with flutter waves discernable in lead II. They are uniform, and occur at a rate of 300/min. Inferiorly directed flutter waves that are positive in V1 are suggestive of typical (cavotricuspid isthmus-dependent), counterclockwise AFL.
(B) Lead V1 and lead II ECG tracings show AFL with moderate ventricular response and variable AV conduction, with flutter waves in lead II at a rate of 272 bpm, consistent with typical AFL.