Paroxysmal atrial fibrillation

This code signifies an irregular, rapid heart rhythm originating in the atria that starts and stops spontaneously, typically lasting less than seven days. It represents an intermittent form of atrial fibrillation where the heart returns to a normal sinus rhythm without intervention or with pharmacologic/electrical cardioversion.

Apply this code when documentation explicitly states "paroxysmal atrial fibrillation" or describes AFib episodes that spontaneously terminate within seven days. This code is appropriate for initial diagnoses, follow-up visits, and hospitalizations where paroxysmal AFib is the primary or a significant secondary diagnosis.

• Distinguish from persistent (I48.11) or long-standing persistent (I48.20) atrial fibrillation, which do not spontaneously terminate.
• Do not use this code if the atrial fibrillation is permanent or continuous.
• Ensure documentation specifies the paroxysmal nature; otherwise, an unspecified AFib code (I48.91) may be more appropriate.