What EKG change is characteristic of atrial flutter?

The characteristic EKG change associated with atrial flutter is the presence of grouped P waves that often resemble a sawtooth pattern, commonly referred to as "F-waves." This distinct pattern arises because, in atrial flutter, there is a rapid reentrant circuit in the atria, leading to a high frequency of atrial depolarizations. These F-waves appear between the QRS complexes and are typically best seen in the inferior leads (II, III, and aVF).

This sawtooth pattern is not only highly distinctive for atrial flutter but also provides valuable information regarding the rate and rhythm of the atria. Understanding this pattern helps clinicians in diagnosing atrial flutter effectively compared to other arrhythmias that might present differently, such as atrial fibrillation with its irregularly irregular rhythm or other conditions leading to widened QRS complexes or prolonged PR intervals.