title: Evidence of specialized conduction cells in human pulmonary veins of patients with atrial fibrillation.
abstract: Specialized Conducting Cells in Human PV.
  
  
  BACKGROUND
  Depolarizations similar to those from the sinus node have been documented from the pulmonary veins after isolation procedures. We assessed the hypothesis that sinus node-like tissue is present in the pulmonary veins of humans.
  
  
  RESULTS
  Pulmonary vein tissue was obtained from five autopsies (four individuals with a history of atrial fibrillation and one without a history of atrial arrhythmias) and five transplant heart donors. Autopsy veins were fixed in formaldehyde and processed for light microscopy to identify areas having possible conductive-like tissue. Areas requiring additional study were extracted from paraffin blocks and reprocessed for electron microscopy. Donor specimens were fixed in formaldehyde for histologic sections and glutaraldehyde for electron microscopy. Myocardial cells with pale cytoplasm were identified by light microscopy in 4 of the 5 autopsy subjects. Electron microscopy confirmed the presence of P cells, transitional cells, and Purkinje cells in the pulmonary veins of these cases.
  
  
  CONCLUSIONS
  Our report is the first to show the presence of P cells, transitional cells, and Purkinje cells in human pulmonary veins. Whether these cells are relevant in the genesis of atrial fibrillation requires further study.
authors.affiliation: Department of Cardiology, Center for Atrial Fibrillation, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Perez-Lugones
authors.forename: James T
authors.initials: JT
authors.lastname: McMahon
authors.forename: Norman B
authors.initials: NB
authors.lastname: Ratliff
authors.forename: Walid I
authors.initials: WI
authors.lastname: Saliba
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schweikert
authors.forename: Nassir F
authors.initials: NF
authors.lastname: Marrouche
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: Saad
authors.forename: José L
authors.initials: JL
authors.lastname: Navia
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: Patrick
authors.initials: P
authors.lastname: Tchou
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000473:pathology*; D002102:Cadaver; D005260:Female; D006329:Heart Conduction System / Q000473:pathology* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000473:pathology* / Q000648:ultrastructure; D011667:Pulmonary Veins / Q000473:pathology* / Q000648:ultrastructure; D012849:Sinoatrial Node / Q000473:pathology / Q000648:ultrastructure