Patent foramen ovale as a cause of cryptogenic ischemic stroke

A patent foramen ovale from an anatomical and physiological point of view is a normal communication between the atria, which is present in utero and allows oxygenated placental blood to reach the fetal arterial circulation. With incomplete postpartum fusion of the primary and secondary septa, a patent foramen ovale is formed. In the last two decades, clinical interest in the problem of the patent foramen ovale is dictated by the fact that its role in the development of such clinical syndromes as ischemic stroke, myocardial infarction, pulmonary embolism, migraine and decompression sickness of divers has been established, as well as the introduction of endovascular techniques for endovascular transcatheter closure of the atrial septal defect. It was found that the frequency of patent foramen ovale detection in patients with cryptogenic stroke is on average 2 times higher than in patients with an established cause of ischemic stroke and ranges from 40% to 50%. Aim of study. Raising awareness of neurologists about the causes, pathogenetic mechanisms of development, methods of diagnosis and treatment of ischemic stroke in patients with patent foramen ovale. Material and methods. To achieve this goal, the results of scientific research devoted to patent foramen ovale as a risk factor for cryptogenic stroke were analyzed. The literature search was carried out in electronic search engines Scopus, eLibrary, PubMed using the keywords: «ischemic stroke», «cryptogenic stroke», «patent foramen ovale», «pathogenesis of ischemic stroke». Scientific articles published between 1878 and 2021 were selected for analysis. 31% of the analyzed works are not older than 5 years. Conclusion. The patent foramen ovale is etiologically associated with cryptogenic stroke. Possible mechanisms of ischemic stroke in patent foramen ovale patients include in situ thrombosis, paradoxical embolism, and atrial arrhythmias. Transcatheter endovascular closure of patent foramen ovale with anatomical signs of a high risk of cerebrovascular events in combination with antiplatelet therapy are indicated for patients with cryptogenic stroke aged 18 to 60 years as an optimal means of secondary prevention of ischemic stroke.