What is the typical atrial rate in atrial flutter?

• A. Atrial rate around 250–350 bpm
• B. 60–100 bpm
• C. 400 bpm
• D. 100–150 bpm

Answer: (A)

In atrial flutter the atria fire in a single, organized reentrant circuit, producing a rapid and regular atrial rhythm. This circuit typically drives the atrial rate at about 250–350 impulses per minute. The ventricles usually respond through the AV node with a conduction ratio that often results in a slower, regular ventricular rate (commonly around 125 bpm with 2:1 conduction), though the exact rate can vary with conduction blocks or medications. The key visual clue on the ECG is the sawtooth flutter waves that mirror that rapid atrial activity. The other rate ranges don’t reflect the characteristic atrial tempo of flutter: normal 60–100 bpm describes sinus rhythm; 400 bpm would be more typical of faster atrial activity such as some atrial tachycardias or atrial fibrillation; 100–150 bpm corresponds more to ventricular rates under certain conduction conditions rather than the atrial rate itself.