Аннотация:Background and aims: Paradoxical embolism (PE) is oneof cause of ischemic stroke (IS), which occurs when thereis an anomaly in the heart in the form of a functioningpatent foramen ovale (PFO). The purpose of the study is toidentify the clinical and morphological features of patientswith PE.Methods: 46 patients from 18 to 59 years old (32 women(69.57%), mean age 36.8±8.7 years) with IS caused by themechanism of PE examined. With transthoracicechocardiography, all were found to have PFO sizes from 1to 3mm with a high degree of shunting blood flow (threeand four degrees).Results: In 11 cases (23.91%) PFO was combined withaneurysm, in 7(15.22%)-with atrial septal hypermobility. Inultrasound examination of the veins of the lower extremitiesand small pelvis, the presence of “fresh” thrombi wasrecorded in one case(2.17%), in 2(4.34%) occlusive postthromboticsclerosis of the lower extremities veins. In 15patients(32.6%), prothrombotic risk factors were identified:homozygous mutation(n=1), heterozygous for Leiden’sfactor(n=2), heterozygous for the fibrinogen gene(n=7),increased factor VIII in combination with von Willebrandfactor activity(n=4), APS(n=1). Four patients were takingoral contraceptives.Conclusion: The study showed that the development of ISby the mechanism of PE is characteristic of young patientswith prothrombotic risk factors, isolated(PFO with a highdegree of shunting blood flow) and associated defects(PFO,aneurysm, myocardial hypermobility) of the interatrialseptum. Ultrasound examination of the veins of the lowerextremities and small pelvis is not decisive for suspectedparadoxical embolism, which is consistent with theliterature data.Disclosure: The authors declare no financial or otherconflicts of interest.