title: Evaluation of left ventricular ejection fraction as a measure of pump performance in patients with chronic mitral regurgitation.
abstract: Left ventricular (LV) ejection fraction may not adequately detect a reduction in LV systolic performance resulting from chronic mitral regurgitation (MR), due to ventricular unloading into the low-impedance left atrium. To determine whether LV ejection fraction sufficiently gauges myocardial function in MR, nine patients were studied using micromanometer-measured LV pressures and biplane cineventriculography before and 1 year after mitral valve surgery. Six control patients were also studied. LV ejection fraction was normal in MR patients, despite an increase in LV end-systolic volume index. LV end-systolic pressure-volume and stress-volume ratios in MR patients were lower than in controls (P < 0.05 and P < 0.01), suggesting that LV systolic performance fell. One year after mitral valve surgery, LV ejection fraction decreased (P < 0.05) even though LV end-systolic volume index (P < 0.05), pressure-volume (P < 0.05), and stress-volume ratios (P < 0.01) all improved. Thus, LV ejection fraction inadequately reflected LV systolic function in MR patients before and after mitral valve surgery.
authors.affiliation: University of Michigan and Veterans Affairs Medical Centers, Ann Arbor, Michigan, USA. stimmis@beaumont.edu
authors.forename: S B
authors.initials: SB
authors.lastname: Timmis
authors.forename: M M
authors.initials: MM
authors.lastname: Kirsh
authors.forename: D G
authors.initials: DG
authors.lastname: Montgomery
authors.forename: M R
authors.initials: MR
authors.lastname: Starling
mesh_terms: D002908:Chronic Disease; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008944:Mitral Valve Insufficiency / Q000503:physiopathology*; D009200:Myocardial Contraction; D013318:Stroke Volume; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left