title: Warfarin-intractable, intraatrial thrombogenesis in a 52-year-old woman with mitral stenosis and chronic atrial fibrillation.
abstract: Thromboembolic events are serious complications of atrial fibrillation (AF). We histologically investigated intraatrial thrombogenesis in a 52-year-old woman with mitral stenosis and chronic AF who had recurrent attacks of cerebral infarction despite continuous warfarin therapy. She underwent cardiac surgery for mitral valve replacement and maze procedure including left atrial thrombectomy. Macroscopic thrombi were found on the endocardium and their surfaces appeared rough and dark red in most areas. Histological examination showed that a single thrombus mass was composed of several tissue layers or blocks on the endocardium. Immunohistochemistry revealed stratum-like accumulations of small platelet aggregate/fibrin clot complexes in the superficial, fresh thrombus layers and multiple neovessel formation in the basal organized tissue layers. This case study suggests that intraatrial thrombi may develop in a stepwise fashion on the endocardium involving platelet aggregate/fibrin clot complex formation.
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Fukuchi
authors.forename: Koji
authors.initials: K
authors.lastname: Kumagai
authors.forename: Masahito
authors.initials: M
authors.lastname: Sakuma
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kagaya
authors.forename: Jun
authors.initials: J
authors.lastname: Watanabe
authors.forename: Koichi
authors.initials: K
authors.lastname: Tabayashi
authors.forename: Kunio
authors.initials: K
authors.lastname: Shirato
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications* / Q000473:pathology; D003328:Coronary Thrombosis / Q000150:complications* / Q000188:drug therapy*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000150:complications* / Q000473:pathology; D010974:Platelet Aggregation / Q000187:drug effects; D017131:Thrombectomy; D014859:Warfarin / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D014859:Warfarin