Which rhythm is represented by a sawtooth pattern on an ECG?

The rhythm associated with a sawtooth pattern on an ECG is atrial flutter. This characteristic waveform is often referred to as "F-waves" or "flutter waves," and it typically manifests as a series of regular, distinct, and sharp deflections that resemble a sawtooth pattern, particularly seen in the inferior leads (II, III, aVF). This pattern is indicative of a rapid reentrant circuit in the atria, leading to coordinated atrial contractions at a high frequency, commonly around 300 beats per minute.

Atrial flutter is different from atrial fibrillation, which has an irregularly irregular rhythm without distinct F-waves. In contrast, normal sinus rhythm would display clearly identifiable P waves followed by QRS complexes in a regular pattern, and ventricular tachycardia generally presents as a series of wide QRS complexes without the organized appearance of F-waves seen in atrial flutter. Understanding these differences is essential for accurately diagnosing and managing various cardiac rhythms in clinical practice.