[Detection of secondary atrial fibrillation following percutaneous foramen ovale closure for cryptogenic stroke using an insertable cardiac monitor: a case report].

A 61-year-old man presented with transient dysarthria and left upper extremity numbness. Head MRI showed an acute infarct in the left temporal lobe and multiple old infarcts in the bilateral cortices. A transesophageal echocardiogram revealed a patent foramen ovale with a large shunt. No deep vein thrombosis was found. He suffered a recurrent cerebral infarction while taking antiplatelet therapy. An insertable cardiac monitor was implanted on the 41st day, and the antiplatelet treatment was changed to warfarin. The insertable cardiac monitor did not detect atrial fibrillation, even when the patient had a recurrent transient ischemic attack on the 57th day under warfarin therapy. The patient underwent percutaneous foramen ovale closure on the 63rd day. On postoperative days 18-25, an insertable cardiac monitor detected brief atrial fibrillation, and he took rivaroxaban for three months. Atrial fibrillation may occur secondary to percutaneous patent foramen ovale closure for cryptogenic stroke. The insertable cardiac monitor may help diagnose the pathogenesis of secondary atrial fibrillation and determine the optimal antithrombotic therapy.