Increased left atrial chamber stiffness in hypertrophic cardiomyopathy.
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.
Sanada
H
H
Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan.
Shimizu
M
M
Sugihara
N
N
Shimizu
K
K
Ino
H
H
Takeda
R
R
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