title: Role of Diastolic Function in Preserved Exercise Capacity in Patients with Reduced Ejection Fractions.
abstract: BACKGROUND
  Some patients with markedly reduced ejection fractions (EFs) (<35%) have preserved exercise performance greater than predicted for age and gender. Because diastolic function may be a determinant of exercise performance, this study was conducted to test the hypothesis that patients with preserved exercise tolerance despite EFs < 35% may have relatively normal diastolic function.
  
  
  METHODS
  Sixty-five subjects with EFs < 35% who underwent exercise Doppler echocardiography and had no inducible ischemia were retrospectively examined. Forty-five subjects with normal EFs (>60%) and preserved exercise capacity were analyzed as a control group.
  
  
  RESULTS
  Sixteen of 65 patients with EFs < 35% had greater than predicted normal exercise capacity for their age and gender, and the remaining 49 patients had reduced exercise capacity. Patients with reduced EFs and preserved exercise capacity had E/e' ratios (mean, 10 ± 4) similar to those of control subjects (mean, 10 ± 3) and lower than those with reduced exercise tolerance (mean, 16 ± 8) (P < .01). In addition, they had better diastolic filling patterns and smaller left atrial sizes than patients with EFs < 35% and reduced exercise capacity. Multivariate logistic regression analyses indicated that E/e' ratio was an independent predictor of preserved exercise capacity in patients with reduced EFs.
  
  
  CONCLUSIONS
  Relatively intact diastolic function contributes to preserved exercise capacity in patients with reduced EFs (<35%).
authors.affiliation: Division of Cardiology and CCU, National Cerebral and Cardiovascular Center, Suita, Japan. Electronic address: tkohara@ncvc.go.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohara
authors.affiliation: Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Iwano
authors.affiliation: Aurora Cardiovascular Services, Milwaukee, Wisconsin.
authors.forename: Vinay
authors.initials: V
authors.lastname: Thohan
authors.affiliation: Cardiology Section, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Dalane W
authors.initials: DW
authors.lastname: Kitzman
authors.affiliation: Cardiology Section, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Bharathi
authors.initials: B
authors.lastname: Upadhya
authors.affiliation: Cardiology Section, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Min
authors.initials: M
authors.lastname: Pu
authors.affiliation: Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi.
authors.forename: William C
authors.initials: WC
authors.lastname: Little
mesh_terms: D000367:Age Factors; D000368:Aged; D002303:Cardiac Output, Low / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D025401:Echocardiography, Stress / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012015:Reference Standards; D012189:Retrospective Studies; D018570:Risk Assessment; D012380:Role; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology*
keywords: Diastole; Echocardiography; Exercise; Heart failure