In atrial flutter, the P waves are described how?

• A. Uniform and tall
• B. Variable and erratic
• C. Flat with no discernible pattern
• D. In a sawtooth configuration

Answer: (D)

In atrial flutter, the P waves are characteristically described as being in a sawtooth configuration. This distinctive pattern is often referred to as "F-waves" or flutter waves, which appear due to a reentrant circuit in the atria causing rapid atrial depolarization. The sawtooth formation typically presents as a series of regular, oscillating waveforms that resemble the teeth of a saw, particularly most observable in the inferior leads of an ECG.

This configuration contrasts sharply with other conditions, where P waves might appear differently—such as being uniform and tall in atrial hypertrophy or flat in atrial fibrillation, where the rhythm is irregular and chaotic. The regularity and specific shape of the flutter waves in atrial flutter make them easily identifiable, particularly for clinicians monitoring cardiac rhythms.