Search

Cryptogenic stroke (CS) is defined as a subtype of stroke associated with a heterogeneous group of pathogenetic mechanisms that remained undetermined in the course of advanced diagnostic research. One third or fourth of the ischemic strokes is cryptogenic. Paradoxical embolism is considered the important cause of cryptogenic stroke and transient ischaemic attack (TIA) in young patients. It may occur via the following: patent foramen ovale (PFO), atrial septal defect (ASD), and pulmonary arteriovenous malformation (PAVM). When interviewing patients with suspected paradoxical embolism to obtain their health history, a practitioner should consider factors associated with Valsalva maneuvers, deep vein thrombosis/PE or predisposing conditions or situations, as well as symptoms of hereditary hemorrhagic telangiectasia (telangiectasia of the skin and mucous membranes, hemorrhagic syndrome) and pulmonary arteriovenous malformations (PAVMs) (shortness of breath, hemoptysis). If paradoxical embolism is suspected, it is necessary to conduct a stepwise diagnostic search, including transcranial Doppler ultrasound with bubble test, contrast-enhanced transesophageal echocardiography, and CT angiopulmonography. Diagnosis of relevant clinical conditions involves a search of atrial tachyarrhythmias, deep vein thrombosis, and thrombophilia. As the pathogenetic role of ASD and PAVMs in the development of embolic cryptogenic stroke is beyond doubt, the clinical significance of PFO should be determined taking into account several factors, including the presence of deep vein thrombosis/PE, the severity of the right-left shunt, the presence of ASD, the RoPE score, and detection of thrombophilia. The secondary prevention techniques of ischemic stroke or TIA with underlying PFO should be selected on a case-by-case basis, depending on the clinical significance of the anomaly, comorbid pathology, life expectancy of the patient: endovascular occlusion, anticoagulant or antiplatelet therapy. The secondary prevention with underlying ASD and LAVM includes surgical techniques such as endovascular occlusion or open surgery followed by monitoring of their effectiveness.

Introduction. The independent role of the atrial septal aneurysm in the occurrence of ischemic stroke remains controversial. In addition to the mechanism of paradoxical embolism against the background of a patent foramen ovale associated with an aneurysm, a number of studies have demonstrated that ischemic stroke can develop due to in situ thrombosis in the aneurysm region.Materials and methods. Description of the clinical case of a patient with atrial septal aneurysm and ischemic stroke while taking hormonal contraceptives. Analyzed all available publications in PubMed on this topic.Results and discussion. Among publications suitable for the criteria, in addition to direct visualization of a blood clot in the area of the atrial septal aneurysm, its independent effect on the occurrence of embolic events was demonstrated. In all analyzed cases, anticoagulants were prescribed for secondary prevention, which is justified on the basis of the hypothesis of in situ thrombosis in the aneurysm region.Conclusion. The analysis of scientific publications showed that the knowledge of this problem is still extremely small. There are no clear criteria, in addition to direct visualization of a blood clot, allowing the atrial septal aneurysm to be considered as a direct cause of ischemic stroke. Nevertheless, the presence of this cardiac abnormality and in combination with risk factors or evidence of prothrombotic status make it possible to regard it as an independent cause of stroke, and qualify the stroke as cardioembolic, which justifies the advisability of prescribing anticoagulants for secondary prevention.