Atrial fibrillation, or AF for short, is one of the most common clinical arrhythmias. In atrial fibrillation, the direction of excitation conduction in the atria is inconsistent, the frequency is fast and irregular, and the atria lose their effective contraction function. In atrial fibrillation, the frequency of atrial excitation is as high as 300-600 beats/min. Although the protective effect of the AV node prevents all these excitations from reaching the ventricles, the ventricular rate (heart rate) can still reach 100-160 beats/min, which is faster than the normal sinus heart rate, and the rhythm is definitely irregular. Patients often present with a fast and irregular self-perceived heartbeat and an irregular pulse. Paroxysmal atrial fibrillation is defined as those who can convert to sinus rhythm on their own within 7 days, usually with a duration of <48 hours; persistent atrial fibrillation is defined as those who persist for more than 7 days and require medication or electrical resuscitation to convert to sinus rhythm; permanent atrial fibrillation is defined as those who cannot convert to sinus rhythm or whose physicians and patients have accepted that the persistence of atrial fibrillation does not intend to convert to sinus rhythm; when atrial fibrillation has persisted for more than 1 year and is considered When atrial fibrillation persists for more than 1 year and conversion to sinus rhythm is being considered (e.g., when radiofrequency ablation is proposed), it is called long-range persistent atrial fibrillation. Atrial fibrillation ECG Classification of primary atrial fibrillation First presentation or first diagnosis of atrial fibrillation, regardless of duration and severity of symptoms. Paroxysmal atrial fibrillation Self-reversal to sinus rhythm within 7 days, usually lasting <48 hours Persistent atrial fibrillation that lasts more than 7 days and requires pharmacological or electrical resuscitation to return to sinus rhythm. Permanent atrial fibrillation that cannot be converted to sinus rhythm, or where the physician and patient have accepted that the persistence of atrial fibrillation is not intended to be converted to sinus rhythm. Long-term persistent atrial fibrillation Atrial fibrillation lasting longer than 1 year and considered for conversion to sinus rhythm.