title: Side-to-side linking of myocardial cells in hypertrophic cardiomyopathy: whole heart microscopic observation with tangential sections.
abstract: By cross-section or longitudinal section, it is difficult to investigate longitudinal features of myocardial cells in the whole heart. Here, introducing the use of tangential sections to obtain longitudinal aspect of myocardial cells in any part of myocardium, the authors evaluated myocardium in the left ventricle in 10 normal hearts and four hearts with hypertrophic cardiomyopathy (HCM). Tangential sections were obtained by peeling the superficial layer of myocardium. After peeling the whole surface, secondary deep layer was peeled. These procedures were repeated more than five times through the wall. Intercalated discs (ICD) were observed immunohistochemically with anti-N-cadherin and antidesmoplakin. In normal hearts, myocardial cells were cut longitudinally and ran parallel in tangential sections. They linked end-to-end with simple and regular ICD with average lengths of 120-130 microm and average sarcomere numbers of 56-65. In HCM hearts, many myocardial cells were cut almost longitudinally running approximately parallel in tangential sections. Myocardial cells frequently showed side-to-side linking characterized by skewed ICD, indistinct ICD counterparts, and longitudinally arranged ICD. Two young HCM hearts had circle-shaped ICD and vacuole-like structures highlighted by immunostaining for N-cadherin, which were actually extracellular structures comparable with irregular side-to-side linking. It is considered that side-to-side linking of myocardial cells is a characteristic microscopic feature in HCM rather than myocardial disarray.
authors.affiliation: Division of Cellular and Organ Pathology, Department of Pathology and Immunology, Medical Center, Akita University School of Medicine, Japan. masuda@med.akita-u.ac.jp
authors.forename: Hirotake
authors.initials: H
authors.lastname: Masuda
authors.forename: Misa
authors.initials: M
authors.lastname: Yamauchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshida
authors.forename: Masato
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nanjo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Asari
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sugita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015820:Cadherins / Q000032:analysis / Q000276:immunology; D002312:Cardiomyopathy, Hypertrophic / Q000473:pathology*; D002648:Child; D051180:Desmoplakins / Q000032:analysis / Q000276:immunology; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry / Q000166:cytology / Q000473:pathology*
chemical_list: D015820:Cadherins; D051180:Desmoplakins