title: Ventricular myocarditis coincides with atrial myocarditis in patients.
abstract: BACKGROUND
  Atrial fibrillation (AF) is a common complication in myocarditis. Atrial inflammation has been suggested to play an important role in the pathophysiology of AF. However, little is known about the occurrence of atrial inflammation in myocarditis patients. Here, we analyzed inflammatory cell numbers in the atria of myocarditis patients without symptomatic AF.
  
  
  METHODS
  Cardiac tissue was obtained postmortem from lymphocytic myocarditis patients (n=6), catecholamine-induced myocarditis patients (n=5), and control patients without pathological evidence of heart disease (n=5). Tissue sections of left and right ventricle and left and right atrium were stained for myeloperoxidase (neutrophilic granulocytes), CD45 (lymphocytes), and CD68 (macrophages). These cells were subsequently quantified in atrial and ventricular myocardium and atrial adipose tissue.
  
  
  RESULTS
  In lymphocytic myocarditis patients, a significant increase was observed for lymphocytes in the left atrial adipose tissue. In catecholamine-induced myocarditis patients, significant increases were found in the atria for all three inflammatory cell types. Infiltrating inflammatory cell numbers in the atrial myocardium correlated positively with those in the ventricles, especially in catecholamine-induced myocarditis patients.
  
  
  CONCLUSIONS
  To a varying extent, atrial myocarditis occurs concurrently with ventricular myocarditis in patients diagnosed with myocarditis of different etiology. This provides a substrate that potentially predisposes myocarditis patients to the development of AF and subsequent complications such as sudden cardiac death and heart failure.
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Dutch Forensic Institute, The Hague, the Netherlands.
authors.forename: Mark P V
authors.initials: MP
authors.lastname: Begieneman
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands. Electronic address: r.emmens@vumc.nl.
authors.forename: Reindert W
authors.initials: RW
authors.lastname: Emmens
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Liza
authors.initials: L
authors.lastname: Rijvers
authors.affiliation: Dutch Forensic Institute, The Hague, the Netherlands.
authors.forename: Bela
authors.initials: B
authors.lastname: Kubat
authors.affiliation: ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Paulus
authors.affiliation: Department of Cardiac Surgery, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Alexander B A
authors.initials: AB
authors.lastname: Vonk
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Rozendaal
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: P Stefan
authors.initials: PS
authors.lastname: Biesbroek
authors.affiliation: Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands.
authors.forename: Diana
authors.initials: D
authors.lastname: Wouters
authors.affiliation: Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands; Department of Hematology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Sacha
authors.initials: S
authors.lastname: Zeerleder
authors.affiliation: Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: van Ham
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Stephane
authors.initials: S
authors.lastname: Heymans
authors.affiliation: ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Albert C
authors.initials: AC
authors.lastname: van Rossum
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands; Department of Cardiac Surgery, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Hans W M
authors.initials: HW
authors.lastname: Niessen
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; ICaR-VU, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Paul A J
authors.initials: PA
authors.lastname: Krijnen
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000209:etiology / Q000473:pathology; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology*; D008297:Male; D009205:Myocarditis / Q000150:complications / Q000473:pathology*
keywords: Atria; Inflammation; Myocarditis; Ventricles