Background:

Paroxysmal atrial fibrillation (PAF) is a form of self-limited and recurrent cardiac arrhythmia, comprising between 25 and 62% of cases, may manifest as a brief episode or periods of varying duration, which are subdiagnosed, mainly in patients with transient ischemic attack and/or stroke.

Clinical case:

76 years old male, who started four days earlier with paresthesia in left upper and lower members, which evolved to left hemiplegia. By submitting multiple infarcts in NMR proceeded to determine origin; the trans-esophageal echocardiogram showed atrial septum aneurysm 22 mm; with Holter monitoring were captured three episodes of paroxysmal atrial fibrillation until the 6th day; the longest lasting 4.3 minutes, prescribing anticoagulation with support.

Conclusions:

Avoid to catalog patients with cryptogenic stroke like unknown origin with negative results in single 24-hour Holter. The discovery of PAF in patients with transient ischemic attack and/or stroke has diagnostic and therapeutic implications on primary and secondary stroke prevention respectively. Prolonged Holter monitoring must be used because the cost-benefit is fully justified.