Why is this left atrial atypical atrial flutter (ECG 1)? Atrial fibrillation can be excluded because nice flutter waves (all look the same) can be clearly identified. With typical right atrial flutter, the reentry circle runs counterclockwise and we see typical saw tooth patterns in the inferior leads (negative flutter waves). The flutter waves are positive in V1 (ECG 2). With typical right atrial flutter with a clockwise reentry circle, the flutter waves in the inferior leads are positive.