Which ECG feature is indicative of atrial flutter?

The characteristic feature of atrial flutter is the presence of a sawtooth waveform pattern, often referred to as “F-waves.” These F-waves typically occur in a regular pattern and can frequently be observed in the inferior leads (II, III, and aVF) on an ECG. This specific waveform results from the rapid, organized electrical activity in the atria, which leads to the signature appearance that is distinct from other types of arrhythmias.

The identification of F-waves is crucial for diagnosing atrial flutter, as they indicate the rapid atrial depolarization occurring at a rate of about 240 to 340 beats per minute. Recognizing this pattern allows clinicians to differentiate atrial flutter from other atrial arrhythmias such as atrial fibrillation, where no distinct F-wave pattern is present. Therefore, the sawtooth appearance formed by the F-waves is a hallmark sign of atrial flutter in an ECG reading.