title: [Effect of angiotensin blockade on the orthostatic response in patients with systemic arterial hypertension].
abstract: OBJECTIVE
  The effect of the treatment of arterial hypertension with angiotensin inhibitors on the autonomic response to orthostatism was studied.
  
  
  METHODS
  In 20 hypertensive patients, enalapril (10 to 20 mg) was administered daily for four weeks. Then, irbesartan (150 to 300 mg) was given for four weeks. Finally, 10 mg of enalapril combined with 150 mg of irbesartan was prescribed for another four weeks. Heart rate variability at rest and during the head-up tilt test with controlled respiration was assessed at the beginning and end of each period.
  
  
  RESULTS
  Mean arterial pressure showed a similar reduction in the three treatment periods. There were no changes in heart rate. Heart rate variability at rest showed differences in the spectral high-frequency component between the control and the treatment periods (p = 0.10). There was an increase in the high-frequency component between the control and the third (p = 0.047) and the fourth periods (p = 0.03). In the head-up tilt test there was a decrease in total spectral high-frequency power.
  
  
  CONCLUSIONS
  There was no increase in orthostatic intolerance with these drugs in hypertensive patients. The absence of changes in heart rate in spite of a decrease in blood pressure suggests resetting of the baroreflex function. The long-term control of hypertension with these drugs may have a favorable effect on heart rate variability, with an increase in parasympathetic activity.
authors.affiliation: Departamento de Electrocardiografía y Electrofisiología. Subdirección de Investigación Clínica. Instituto Nacional de Cardiología Ignacio Chávez. México, D.F. Mexico.
authors.forename: Liliana
authors.initials: L
authors.lastname: Galván
authors.forename: Kathrine
authors.initials: K
authors.lastname: Jáuregui-Renaud
authors.forename: Manlio F
authors.initials: MF
authors.lastname: Márquez
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Hermosillo
authors.forename: Manuel
authors.initials: M
authors.lastname: Cárdenas
mesh_terms: D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011187:Posture
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril