In what way does atrial flutter differ from atrial fibrillation?

Atrial flutter is characterized by organized and rapid electrical activity in the atria, typically manifesting as a regular atrial rhythm often described as a "sawtooth" pattern on an electrocardiogram (ECG). This organized rhythm contrasts with atrial fibrillation, which is characterized by irregular and chaotic electrical activity in the atria, leading to an irregularly irregular heart rate and absence of distinct P waves on the ECG.

The difference in organization between atrial flutter and atrial fibrillation is crucial for understanding their pathophysiology as well as their management. In atrial flutter, a reentrant circuit is often involved, creating a continuous loop that results in consistent depolarization of the atrial muscle. In contrast, atrial fibrillation involves multiple ectopic foci that contribute to a rapid and erratic electrical pattern. This understanding informs treatment approaches and helps predict potential complications associated with each arrhythmia.