title: Divergent cardiac response to exercise in essential hypertension vs. normotension and the effect of enalapril.
abstract: The aims of this study were to examine (1) the cardiac response to exercise in essential hypertension and (2) the effect of long-term enalapril treatment on cardiac reserve. Ten normotensive control subjects and 15 patients with moderate, essential hypertension underwent radionuclide ventriculography during graded, supine exercise (0 W-50 W-100 W). The hypertensive patients were studied during monotherapy using hydrochlorothiazide and 3 and 12 months after supplementation with enalapril 10-40 mg o.d. During exercise, the control subjects demonstrated a 17% increase in left ventricular ejection fraction (LVEF) mediated by a 30% decrease in end-systolic volume, a small increase in stroke volume and a minor biphasic (increase-decrease) change in end-diastolic volume. In the hypertensive patients, both the end-diastolic and the end-systolic volume increased substantially with no increase in LVEF, although stroke volume increased by 33%. Long-term therapy with enalapril induced only a minor change towards a more normal pattern of cardiac response to exercise. The hypertensive patients increased their stroke volume during exercise by recruiting preload reserve instead of increasing contractility. Long-term treatment with enalapril had little, if any, effect on this abnormal cardiac response.
authors.affiliation: Department of Clinical Physiology, Glostrup University Hospital, Copenhagen, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Gadsbøll
authors.forename: S
authors.initials: S
authors.lastname: Rasmussen
authors.forename: B H
authors.initials: BH
authors.lastname: Jensen
authors.forename: A
authors.initials: A
authors.lastname: Leth
authors.forename: J
authors.initials: J
authors.lastname: Giese
authors.forename: P F
authors.initials: PF
authors.lastname: Høilund-Carlsen
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D002306:Cardiac Volume / Q000187:drug effects*; D004359:Drug Therapy, Combination; D004656:Enalapril / Q000494:pharmacology*; D015444:Exercise / Q000502:physiology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D006334:Heart Function Tests; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D018709:Statistics, Nonparametric; D013318:Stroke Volume / Q000187:drug effects*; D016683:Supine Position / Q000502:physiology; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents; D006852:Hydrochlorothiazide; D004656:Enalapril