title: Increased left atrial chamber stiffness in hypertrophic cardiomyopathy.
abstract: OBJECTIVE
  To investigate left atrial chamber stiffness and its influence on left atrial and left ventricular functions in hypertrophic cardiomyopathy.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Department of internal medicine in a university teaching hospital.
  
  
  METHODS
  Five control subjects, six patients with essential hypertension, and 11 patients with hypertrophic cardiomyopathy.
  
  
  METHODS
  Measurement of left atrial pressure by a tip micromanometer and of real-time left atrial volume from left atrial cineangiograms.
  
  
  METHODS
  Left atrial stiffness constant determined by fitting the ascending limb of the v loop of the left atrial pressure-volume relation to an exponential curve.
  
  
  RESULTS
  The mean (SD) left atrial chamber stiffness constant was significantly larger in patients with hypertrophic cardiomyopathy than in controls (0.063 (0.018) v 0.041 (0.006), p < 0.05) and was correlated with left ventricular wall thickness (r = 0.560, p < 0.01). Left atrial reservoir volume (left atrial emptying volume before atrial contraction) was significantly smaller in patients with hypertrophic cardiomyopathy than in the controls (7.3 (2.1) v 12.5 (4.4) ml/m2, p < 0.01) and was inversely correlated with the left atrial chamber stiffness constant (r = -0.598, p < 0.01). The cardiac index was inversely correlated with the left atrial chamber stiffness constant (r = -0.542, p < 0.01).
  
  
  CONCLUSIONS
  Left atrial chamber stiffness was increased in patients with hypertrophic cardiomyopathy and this affected the left atrial reservoir function. This may in turn have affected cardiac output.
authors.affiliation: Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sanada
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: N
authors.initials: N
authors.lastname: Sugihara
authors.forename: K
authors.initials: K
authors.lastname: Shimizu
authors.forename: H
authors.initials: H
authors.lastname: Ino
authors.forename: R
authors.initials: R
authors.lastname: Takeda
mesh_terms: D016279:Atrial Function, Left / Q000502:physiology*; D002312:Cardiomyopathy, Hypertrophic / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011312:Pressure; D011446:Prospective Studies; D016277:Ventricular Function, Left / Q000502:physiology