title: Ectopic nodal structures in a patient with atrial tachycardia originating from the mitral valve annulus.
abstract: We report a case, which we believe to be rare, of adenosine-sensitive atrial tachycardia (AT) originating from the mitral valve annulus. The patient, a 73-year-old woman, died of unrelated cause 4 years after radiofrequency (RF) ablation therapy. Histologically, fibrous replacement of atrial musculature by mature collagenous tissue produced by the RF current was observed at the left inferior atrioventricular junction. In serial sections that included the coronary sinus, two distinct nodal structures containing small, pale myocytes within the fibrous tissue matrix were identified around the region of the ablation lesion. Our case appears to be a unique representation of tissue that was associated with the occurrence and maintenance of AT.
authors.affiliation: Second Department of Pathology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan. gm00350@med.showa-u.ac.jp
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Matsuyama
authors.forename: Shin
authors.initials: S
authors.lastname: Inoue
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tanno
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Makino
authors.forename: Genyo
authors.initials: G
authors.lastname: Ogawa
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sakai
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Katagiri
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Ota
mesh_terms: D000368:Aged; D002828:Choristoma; D005260:Female; D006329:Heart Conduction System / Q000002:abnormalities*; D006801:Humans; D008943:Mitral Valve / Q000002:abnormalities* / Q000473:pathology*; D012849:Sinoatrial Node / Q000473:pathology*; D013612:Tachycardia, Ectopic Atrial / Q000150:complications* / Q000175:diagnosis*