title: Isolated pulmonary arteriovenous fistula without Rendu-Osler-Weber disease as a cause of cryptogenic stroke.
abstract: There has been uncertainty as to whether a right to left shunt through an isolated pulmonary arteriovenous fistula (P-AVF) without Rendu-Osler-Weber (ROW) disease can cause paradoxical brain embolism. A population of 747 acute ischaemic stroke patients was examined to determine the frequency and clinical characteristics of those patients who had an isolated P-AVF. The presence of a P-AVF was determined as follows. On patients with a stroke of undetermined cause, both transoesophageal echocardiography and transcranial Doppler with saline contrast medium was performed to detect a right to left shunt. If a P-AVF was then suspected, selective pulmonary angiography and enhanced chest CT was performed to confirm the presence of the P-AVF. Four patients (0.5%) were diagnosed as having a stroke associated with an isolated P-AVF. All the patients were middle-aged women (mean age 61 years). In all these patients, the P-AVF could not have been suspected on physical findings or chest x ray. The P-AVF was always single and located in the lower lobe. All the patients had asymptomatic deep venous thrombosis, and three patients developed pulmonary embolism. As D-dimer and thrombin-antithrombin complex were elevated in all patients, this indicated an activation of both fibrinolytic and thrombin activity. Our results show that an isolated P-AVF without ROW disease can cause paradoxical brain embolism. Thus, the existence of an isolated P-AVF as a right to left shunt in patients with a stroke of unknown origin should not be overlooked, even if a P-AVF is not suggested by the initial physical findings or chest x ray.
authors.affiliation: Cerebrovascular Division, Department of Medicine, National Cardiovascular Center, Fujishirodai, Suita, Osaka, Japan. kimurak@hsp.ncvc.go.jp
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Minematsu
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
mesh_terms: D000368:Aged; D000990:Antithrombin III; D001164:Arteriovenous Fistula / Q000150:complications* / Q000175:diagnosis*; D002533:Cerebral Angiography; D002544:Cerebral Infarction / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*; D003937:Diagnosis, Differential; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D010447:Peptide Hydrolases / Q000097:blood; D011651:Pulmonary Artery / Q000002:abnormalities*; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000097:blood / Q000175:diagnosis*; D020246:Venous Thrombosis / Q000150:complications
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C046193:antithrombin III-protease complex; C036309:fibrin fragment D; D000990:Antithrombin III; D010447:Peptide Hydrolases