title: Hemodynamic alterations in hypertensive patients at rest and during passive head-up tilt.
abstract: OBJECTIVE
  Hypertension is characterized by increased vascular resistance and arterial stiffness, but information about upright hemodynamics is scarce. We compared hemodynamics in hypertensive versus normotensive patients at rest and during passive head-up tilt.
  
  
  METHODS
  Volunteers (n = 387, 19-72 years) without antihypertensive medication were recorded using continuous tonometric pulse wave analysis and whole-body impedance cardiography. Seated office blood pressure was 4/10  mmHg (systolic/diastolic) higher than average supine values during hemodynamic measurements. As there is no accepted cut-off for hypertension during tilt-table tests, supine level at least 135/85  mmHg defined hypertension (n = 155) versus normotension (n = 232). Age, BMI, and proportion of men were higher among hypertensives (49 vs. 42 years, 28 vs. 25, 55 vs. 38%, respectively), and analyses were adjusted for these differences.
  
  
  RESULTS
  Both at rest and during head-up tilt radial and aortic blood pressure and pulse pressure, cardiac index (CI) and work, systemic vascular resistance (SVR), and augmentation pressure were higher in hypertensive patients (P < 0.05 for all). Adjusted linear regression analyses showed that during passive head-up tilt aortic SBP and pulse pressure, stroke index, and left cardiac work index decreased less; heart rate increased less; and aortic DBP and SVR increased more in hypertensive patients (P < 0.05 for all); whereas reduction in CI and augmentation index did not differ between the groups.
  
  
  CONCLUSIONS
  Not only supine hemodynamics, but also responses to head-up tilt differed between normotensive and hypertensive patients, indicating functional alterations beyond increased vascular resistance and higher arterial stiffness in hypertension.
authors: School of Medicine, University of Tampere, Tampere, Finland. antti.tikkakoski@uta.fi
authors: Antti J
authors: AJ
authors: Tikkakoski
authors: Anna M
authors: AM
authors: Tahvanainen
authors: Miia H
authors: MH
authors: Leskinen
authors: Jenni K
authors: JK
authors: Koskela
authors: Antti
authors: A
authors: Haring
authors: Jani
authors: J
authors: Viitala
authors: Mika A P
authors: MA
authors: Kähönen
authors: Tiit
authors: T
authors: Kööbi
authors: Onni
authors: O
authors: Niemelä
authors: Jukka T
authors: JT
authors: Mustonen
authors: Ilkka H
authors: IH
authors: Pörsti
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D018667:Tilt-Table Test; D014655:Vascular Resistance; D059289:Vascular Stiffness