After how many days is atrial fibrillation considered chronic?

Atrial fibrillation is classified based on the duration of the episode, and the criteria for distinguishing between paroxysmal (intermittent) and chronic (persistent) atrial fibrillation hinges on the duration of the episode. An episode that lasts longer than seven days is considered to have transitioned from paroxysmal atrial fibrillation to persistent atrial fibrillation.

When atrial fibrillation persists for more than seven days, it indicates that it is unlikely to terminate spontaneously and may require medical intervention or management. This distinction is crucial for treatment planning and patient management, as the approach to patients with persistent or chronic atrial fibrillation may differ from that for those with occasional episodes. This is why the correct answer is seven days, marking the threshold for chronic classification in the clinical context of managing atrial fibrillation.