title: Factors determining left atrial kinetic energy in patients with chronic mitral valve disease.
abstract: BACKGROUND
  Increased left atrial (LA) work is a major contributor to LA fatigue, LA failure and atrial fibrillation in patients with mitral stenosis (MS) and mitral valvular regurgitation (MVR). The present study was undertaken to define factors that determine LA work in patients with chronic mitral valve disease.
  
  
  METHODS
  Peak left atrial kinetic energy (LAKE)was used as an index of LA work in 14 patients with MS, 14 with MVR, and 19 normal subjects matched for age and gender with MS and MVR patients. LA stroke volume and ejection fraction were measured from the biplane area-length method using echo techniques. Peak LAKE was obtained from the formula 1/2 mv2, where m = LA stroke volume x 1.06 (blood's specific gravity) and v = transmitral Doppler A-wave velocity.
  
  
  RESULTS
  Stepwise regression analysis often clinical and echocardiographic parameters demonstrated that in MS, mitral valve area (r2 = 0.43) and LA maximal volume (r2 = 0.62), in MVR, only LA maximal volume (r2 = 0.42) contributed independently to LAKE. LAKE was greater in MS and MVR compared to control subjects while LA ejection fraction was similar in all groups.
  
  
  CONCLUSIONS
  It is concluded that LA work is markedly increased in patients with chronic mitral valve disease. Increased LA work in chronic mitral valve disease may contribute to LA fatigue, LA failure, and atrial fibrillation.
authors.affiliation: Department of Internal Medicine, The Ohio State University, Columbus, OH, USA.
authors.forename: Konstantinos D
authors.initials: KD
authors.lastname: Boudoulas
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Sparks
authors.forename: Stanley E
authors.initials: SE
authors.lastname: Rittgers
authors.forename: Charles F
authors.initials: CF
authors.lastname: Wooley
authors.forename: Harisios
authors.initials: H
authors.lastname: Boudoulas
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology; D016275:Atrial Function / Q000502:physiology*; D016279:Atrial Function, Left / Q000502:physiology; D001794:Blood Pressure; D003627:Data Interpretation, Statistical; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology*; D008946:Mitral Valve Stenosis / Q000503:physiopathology*; D012044:Regression Analysis