title: Treadmill exercise in apparently asymptomatic patients with moderate or severe aortic stenosis: relationship between cardiac index and revealed symptoms.
abstract: OBJECTIVE
  To test whether symptoms revealed on exercise testing in patients with moderate or severe aortic stenosis are associated with changes in left ventricular systolic function and to investigate the ability of resting measures to predict peak cardiac index.
  
  
  METHODS
  In a prospective study of asymptomatic aortic stenosis, 38 patients with a median age of 63 years (range 29-83) and an effective aortic orifice area by the continuity equation of less than 1.5 cm(2) had echocardiography, measurement of blood B-type natriuretic peptide (BNP) level and exercise haemodynamic testing using an inert gas rebreathing device.
  
  
  RESULTS
  Revealed symptoms occurred in 10 patients in whom peak cardiac index (p=0.002), stroke index (p=0.024) and maximum oxygen consumption (VO(2)) (p=0.003) were lower than in those without symptoms. Univariate predictors of peak cardiac index were Doppler tissue peak systolic velocity (p=0.004, r=0.45), the ratio of peak transmitral E velocity to Doppler tissue Ea velocity (p=0.039, r=-0.34) and log BNP (p<0.001, r=-0.71). The only independent predictor of peak cardiac index was the log BNP level (p<0.001, r=-0.71).
  
  
  CONCLUSIONS
  Revealed symptoms on treadmill exercise in apparently asymptomatic aortic stenosis were associated with lower peak myocardial VO(2) and lower peak stroke index during exercise. The strongest resting predictor of revealed symptoms and of peak cardiac index was the blood BNP level.
authors.affiliation: Valve Study Group, Guy's and St Thomas Hospitals Foundation Trust, London, UK.
authors.forename: Ronak
authors.initials: R
authors.lastname: Rajani
authors.forename: Helen
authors.initials: H
authors.lastname: Rimington
authors.forename: John B
authors.initials: JB
authors.lastname: Chambers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D011446:Prospective Studies; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology
chemical_list: D020097:Natriuretic Peptide, Brain