Abstract
With the development of diagnostic options, such as long-term monitoring of cardiac rhythm and routine transesophageal echocardiography (TEE), the number of strokes is increasing, with a proven correlation with heart disease. If the standard examination protocol incl.
Using the above methods we can detect some rare diseases leading to stroke. Such diseases include pulmonary arteriovenous malformations (PAVM).
It is a vascular anomaly allowing direct communication between the pulmonary artery leading the oxygenated blood to the lungs and the vein leading the oxygenated blood from the lungs back to the heart. This communication leads to the emergence of a high-flow and low-resistance right-to-left short circuit due to the absence of an interstitial capillary bed.
Thus, PAVM may be the path of paradoxical embolization of thrombi from the venous bed of the large circulation to the CNS or directly the site of thrombus formation. The prevalence of PAVM is reported 1: 2,630 based on data obtained from CT screening lung cancer screening programs.
In patients with cryptogenic stroke, the prevalence is reported to be higher. Approximately 80-90% of all PAVMs are associated with Rendu-Osler-Weber Syndrome, or hereditary hemorrhagic teleangiectasis (HHT), with about 15-35% of HHT patients having PAVM.
It is fibrovascular dysplasia with an autosomal dominant heredity and a prevalence of approximately 1: 5,000 worldwide. HHT is characterized by the presence of teleangiectases and arteriovenous malformations of the skin, mucous membranes and internal organs with a familial-bound incidence.