Concurrent Patent Foramen Ovale and Pulmonary Arteriovenous Malformation Etiology

BACKGROUND: Patent foramen ovale (PFO) and pulmonary arteriovenous malformations (PAVMs) are congenital vascular abnormalities that can lead to right-to-left shunting, potentially causing paradoxical embolism. CASE SUMMARY: We describe a case of a 39-year-old woman who presented with syncope and left-sided facial numbness; her brain imaging confirmed a subacute lacunar infarct in the left thalamus. A transthoracic echocardiogram showed a PFO with moderate to severe right-to-left shunting. The patient underwent successful PFO closure. Postprocedurally, she developed transient hypotension. Computed tomography of the chest, abdomen, and pelvis was performed to exclude bleeding. Incidentally, a PAVM in the right middle lobe of the lung was identified, which was then successfully closed with embolization. DISCUSSION: PFO is a well-established cause of paradoxical embolism, but rarer extracardiac shunts such as PAVMs can coexist and contribute to cryptogenic stroke. TAKE-HOME MESSAGE: A comprehensive evaluation for multiple shunt sources is essential in younger patients with cryptogenic stroke.