Background: Atrial fibrillation (AF) after transcatheter closure of patent foramen ovale (PFO) is not a rare complication. However little is known about the effect of atrial septal device implantation on the occurrence of this arrhythmia.

Objective: The aim of this study was to evaluate the occurrence of AF in two groups of patients who underwent transcatheter PFO closure: those with a previous cryptogenic stroke and those with other index events respectively.

Methods: Patient population included 276 patients with documented PFO who underwent percutaneous closure at our institution. Patients were grouped on the basis of two distinct clinical presentations: a) 246 patients with history of previous cryptogenic cerebrovascular ischemic event (CIE) or b) 30 patients with other different index events. AF after PFO closure was detected by 12-lead electrocardiography or by 24-h-Holter monitoring.

Results: During a mean follow-up of 17 months, new-onset AF was documented in 10 patients (4%), all included in the group with a previous cryptogenic CIE, at a mean of 1.6 months post-procedure. Comparing patients with and without AF, age (mean 56 years vs 46 years, p = 0.012) and left atrial size (4.4 cm vs 3.7 cm, p = 0.001) resulted to differ significantly. The type and size of occluder devices do not seem to impact the occurrence of AF after PFO closure.

Conclusions: In patients presenting with cryptogenic stroke, especially in those with slightly enlarged left atria and age above 50–55 years, detection of a PFO should prompt an extended monitoring for excluding AF.