title: Reduced right atrial contractile force in patients with left ventricular diastolic dysfunction: A study in human atrial fibers-contractile force and diastolic dysfunction.
abstract: OBJECTIVE
  The aim of our study was to evaluate right heart contractile force in patients with diastolic dysfunction (DD) with preserved left heart ejection fraction undergoing cardiac surgery. We examined the contractile properties of skinned human fibers obtained from the right auricle in two groups (DD and controls).
  
  
  METHODS
  Right atrial tissue from 64 patients, who were undergoing cardiac surgery, were collected before extracorporal circulation. Tissue was conserved and prepared as "skinned fibers". We exposed the dissected fibers to increasing calcium concentrations and recorded the force values.
  
  
  RESULTS
  Patients with DD develop significantly less force at middle and higher calcium concentrations pCa 4.0: DD 2.58 ± 0.4 mN, controls 5.32 ± 0.4 mN, p = 0.02; pCa 5.5: DD 1.14 ± 0.3 mN, controls 1.45 ± 0.3 mN, p = 0.03. DD significantly correlates with left ventricular hypertrophy (LVH; p = 0.03). DD did not significantly occur more often in patients with mitral valve insufficiency, aortic insufficiency or stenosis, or coronary heart disease (all p > 0.10). LVH, which was associated with DD, correlated significantly with mitral valve prolapse (p = 0.05), aortic valve stenosis (p = 0.02), and mitral valve insufficiency (p = 0.03).
  
  
  CONCLUSIONS
  Contractile force is significantly reduced in right atrial skinned human fibers with DD. DD is significantly associated with LVH, but emerges independently from underlying pathologies like valve diseases or coronary heart disease. This underlines the hypothesis that impairment of contractile capacity directly results from DD-independent from volume or pressure overload due to valvular or ischemic heart disease.
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany. Electronic address: constanze.bening@googlemail.com.
authors.forename: Constanze
authors.initials: C
authors.lastname: Bening
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: Anjuli
authors.initials: A
authors.lastname: Sikand
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: Lars Oliver
authors.initials: LO
authors.lastname: Conzelmann
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Stumpf
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
authors.forename: Christian-Friedrich
authors.initials: CF
authors.lastname: Vahl
mesh_terms: D000328:Adult; D000368:Aged; D016280:Atrial Function, Right / Q000502:physiology*; D016022:Case-Control Studies; D003971:Diastole / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000601:surgery
keywords: calcium sensitivity; diastolic dysfunction; skinned fiber