Pulmonary Arteriovenous Malformation can be Associated with Embolic Stroke of Undetermined Source (ESUS)

Pulmonary arteriovenous malformations (PAVMs) are rare vascular anomalies. Alternative designations are pulmonary arteriovenous fistulae or aneurysms. Although mostly asymptomatic, PAVMs can cause respiratory symptoms due to right-to-left shunt. The central nervous system is a potential target for complications, including stroke, as a result of paradoxical embolism. In this report, the authors describe an unusual case of cerebral emboli caused by paradoxical embolism through a PAVM, presenting with a broad pathology including orthodeoxia, central cyanosis and digital clubbing, which should be kept in mind since misdiagnosis may cause severe morbidity in young adults. LEARNING POINTS: Pulmonary arteriovenous fistulae, although rare, must be considered in the presence of dyspnoea, cyanosis, hypoxaemia/orthodeoxia and stroke. In young adults with embolic stroke of undetermined source (ESUS), paradoxical embolism has to be ruled out. Meticulous anamnesis and physical examination can guide diagnostic investigation, reducing hospitalization time and superfluous complementary examinations.