What is a hallmark sign of atrial flutter on an ECG?

The hallmark sign of atrial flutter on an electrocardiogram (ECG) is the presence of a sawtooth pattern of P waves, commonly referred to as F-waves. This distinct pattern typically appears as a series of sharp, pointed waves that resemble a sawtooth and is most often seen in the inferior leads of the ECG such as II, III, and aVF. This pattern indicates that there is a rapid reentrant circuit in the atria, leading to the characteristic fluttering of the atrial muscle.

In atrial flutter, the atrial rate can be quite high (often around 300 beats per minute), but the ventricular rate may vary depending on how many of the atrial impulses are conducted through the AV node. The F-waves are an important indicator for diagnosing atrial flutter and differentiating it from other arrhythmias. Recognizing this pattern is crucial for healthcare professionals, as it guides appropriate treatment and management of the condition.

Other choices, while related to ECG interpretation, do not specifically identify atrial flutter itself. For instance, flat T waves or shortened QRS complexes could occur in various clinical scenarios and do not provide a specific identification of atrial flutter like the F-wave does. Regular R