title: Systemic and left ventricular responses to exercise stress in asymptomatic patients with valvular aortic stenosis.
abstract: Patients with heart disease may have myocardial ischemia or left ventricular (LV) dysfunction without symptoms. The exercise responses of 14 asymptomatic patients with valvular aortic stenosis (AS) were studied using treadmill testing, thallium-201 scintigraphy and radionuclide angiography. Compared with age- and gender-matched control subjects, patients with AS demonstrated reduced exercise tolerance (10.7 +/- 2.5 vs 13.3 +/- 4.2 min; p = 0.06) and maximal oxygen consumption (26.7 +/- 6.3 vs 36.3 +/- 9.5 ml O2/min/kg; p = 0.004) associated with decreased peak systolic blood pressure response to exercise (177 +/- 18 vs 214 +/- 42 mm Hg; p less than 0.004). Ten of 14 patients developed ST-segment depression during exercise, only 3 of whom had reversible thallium defects. Patients with AS tended to have greater LV ejection fractions at rest (65 +/- 11 vs 58 +/- 7; p = 0.08) and significantly decreased early peak filling rates (4.8 +/- 1.3 vs 6.1 +/- 0.6 stroke volume/s; p = 0.003) compared with those of control subjects. During maximal supine exercise, patients with AS had less of an increase in ejection fraction (2 +/- 9 vs 15 +/- 7%; p less than 0.001) associated with a decrease in end-diastolic (-7 +/- 15 vs +5 +/- 16%; p = 0.06) and stroke (-6 +/- 17 vs +30 +/- 13%; p less than 0.001) volumes from baseline measurements.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Cardiovascular Diagnosis, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: C A
authors.initials: CA
authors.lastname: Clyne
authors.forename: J A
authors.initials: JA
authors.lastname: Arrighi
authors.forename: B J
authors.initials: BJ
authors.lastname: Maron
authors.forename: V
authors.initials: V
authors.lastname: Dilsizian
authors.forename: R O
authors.initials: RO
authors.lastname: Bonow
authors.forename: R O
authors.initials: RO
authors.lastname: Cannon
mesh_terms: D000328:Adult; D000368:Aged; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003971:Diastole; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011877:Radionuclide Imaging; D013318:Stroke Volume; D013794:Thallium Radioisotopes; D016277:Ventricular Function, Left
chemical_list: D013794:Thallium Radioisotopes