Atrial fibrillation includes paroxysmal atrial fibrillation and persistent atrial fibrillation. Patients with paroxysmal atrial fibrillation may have a normal heart rate during non-attack periods. In contrast, those with persistent atrial fibrillation continuously experience atrial fibrillation rates, presenting with irregular heart sounds of varying intensity.

A normal electrocardiogram displays P waves, QRS complexes, and T waves. However, patients with atrial fibrillation either do not exhibit P waves or show irregularly sized, serrated P waves resembling dog teeth, suggesting atrial fibrillation.

Therefore, although atrial fibrillation is associated with arrhythmias, individuals with paroxysmal atrial fibrillation may have a normal heart rate but experience repeated palpitations, chest tightness, discomfort in the precordial region, and fatigue.

Therefore, patients who frequently experience palpitations should undergo a 24-hour Holter monitor test or consider esophageal electrophysiological examinations to rule out arrhythmic disorders, such as atrial fibrillation and supraventricular tachycardia. Hence, a normal heart rate does not exclude the presence of atrial fibrillation in individuals with corresponding symptoms.