Which ECG pattern is typically seen in atrial flutter?

• A. P Waves with PR Interval Lengthened
• B. Oscillating Capacitor Waves
• C. Sawtooth Waves
• D. No P Waves, Irregularly Irregular

Answer: (C)

Atrial flutter shows a rapid, organized atrial rhythm that creates a distinctive sawtooth pattern of flutter waves on the ECG, typically around 250–350 atrial depolarizations per minute. Because these rapid atrial waves replace the normal P waves, you won’t see discrete P waves with a measurable PR interval. The QRS complexes may appear regular if the AV node conducts at a steady ratio (like 2:1 or 4:1), but the key clue is the repeating sawtooth flutter waves, best seen in leads II, III, aVF, or V1.

The other patterns don’t fit as well: a lengthened PR interval with normal P waves points to first-degree AV block, not flutter; something described as oscillating capacitor waves isn’t a standard ECG finding for this rhythm; and no P waves with an irregularly irregular rhythm describes atrial fibrillation, which lacks organized atrial activity and shows chaotic baseline activity with irregular intervals.

Sawtooth flutter waves are the hallmark that identifies atrial flutter.