Which arrhythmia is often described as having a "sawtooth" pattern on an ECG?

Atrial flutter is characterized by a distinctive "sawtooth" pattern on the electrocardiogram (ECG), often referred to as "f waves" or "flutter waves." This pattern occurs due to a reentrant circuit in the atria, typically leading to a rapid atrial rate, usually around 240 to 340 beats per minute. The sawtooth appearance is particularly noticeable in leads II, III, and aVF, where the repetitive nature of the atrial impulses creates a consistent, jagged pattern, resembling a sawtooth.

This identification is critical in differentiating atrial flutter from other arrhythmias, as other conditions do not display this characteristic waveform. For instance, ventricular tachycardia would have a wide, regular QRS complex and not show the sawtooth pattern, while supraventricular tachycardia typically presents with a narrow QRS complex and lacks a distinct flutter wave pattern altogether. Bradycardia involves a slow heart rate and does not exhibit the flutter waves seen in atrial flutter. Understanding this ECG finding is essential in the recognition and management of atrial flutter.