title: Effects of valve replacement on ventricular mechanics in mitral regurgitation and aortic stenosis.
abstract: BACKGROUND
  This study in humans assessed changes in left ventricular function early and late after correction of mitral regurgitation (MR) (n = 9) or aortic stenosis (AS) (n = 10).
  
  
  METHODS
  Ventricular function was measured with radionuclide and micromanometer-derived pressure-volume loops during preload manipulation, thermodilution cardiac outputs, and echocardiograms. Late radionuclide and echocardiographic data were acquired at 24 hours and 20 months.
  
  
  RESULTS
  Perioperative left ventricular performance (stroke work-end-diastolic volume relationship) did not change for patients with MR or AS. Significant changes in afterload occurred: ejection fraction (MR, 0.49 to 0.37; AS, 0.54 to 0.60; both, p = 0.013), mean left ventricular ejection pressure (MR, 73 to 91 mm Hg; AS, 138 to 93 mm Hg; both, p < 0.01), and end-systolic wall stress (MR, 26 to 42 x 10(3) dynes/cm2; AS, 37 to 22 x 10(3) dynes/cm2; both, p < 0.01). Ejection efficiency improved for MR patients (0.69 +/- 0.26 to 1.0 +/- 0.15; p < 0.05). The 20-month data showed improved New York Heart Association functional class, normal resting ejection fraction, and normal exercise response for both groups.
  
  
  CONCLUSIONS
  Early after operation, a significant change in left ventricular load was seen with correction of MR and AS. Data obtained late after operation showed improvement consistent with ventricular remodeling.
authors.affiliation: Division of Thoracic Surgery, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Harpole
authors.forename: S A
authors.initials: SA
authors.lastname: Gall
authors.forename: W G
authors.initials: WG
authors.lastname: Wolfe
authors.forename: J S
authors.initials: JS
authors.lastname: Rankin
authors.forename: R H
authors.initials: RH
authors.lastname: Jones
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002302:Cardiac Output; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011875:Radionuclide Angiography; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left