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Clinical Autonomic Research

, Volume 13, Issue 6, pp 433–438 | Cite as

Cardiac autonomic responses to progressive head-up tilt in individuals with paraplegia

  • Jill M. Wecht
  • Ronald E. De Meersman
  • Joseph P. Weir
  • Ann M. Spungen
  • William A. Bauman
RESEARCH ARTICLE

Abstract.

Beat-to-beat fluctuations in heart rate are partially controlled by the autonomic nervous system and may be altered by a spinal cord injury. The purpose of the present investigation was to examine the role of the autonomic nervous system in modulating the heart rate response to head-up tilt (HUT) in subjects with low lesion paraplegia. Nineteen subjects with paraplegia and nine age-, height-, and weight-matched control subjects consented to participate. A three lead ECG was used to acquire heart rate (HR), cardiac sympathetic [low frequency component of R-R interval variability (LFRRI)], vagal [high frequency component of R-R interval variability (HFRRI)] and sympatho-vagal balance (LF/HF). A finger photoplethysmograph was used to assess beat-to-beat blood pressure for the estimation of sympathetic vasomotor tone [low frequency component of peak systolic blood pressure variability (LFSBP)]. The results showed a significant main effect for tilt angle for the HR response to HUT, which was comparable between the groups. LFRRI was significantly increased (P < 0.001) and HFRRI was significantly reduced (P < 0.001) across tilt angle in the control group, whereas subjects with paraplegia demonstrated no significant change in LFRRI, but significantly reduced HFRRI (P < 0.001) across tilt angle. There was a significant interaction effect for LF/HF (P < 0.05). LFSBP was significantly reduced in the group with paraplegia compared to controls (P < 0.05). These findings suggest that although cardiac autonomic control is intact, there is a blunted sympathetic response to HUT in subjects with low lesion paraplegia, which may implicate an altered baroreceptor response to acute orthostatic provocation.

Key words

head-up tilt cardiovascular-autonomic modulation vagal activity sympathetic activity peripheral vasomotor tone 

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Copyright information

© Steinkopff Verlag 2003

Authors and Affiliations

  • Jill M. Wecht
    • 1
    • 2
    • 3
    • 4
  • Ronald E. De Meersman
    • 5
  • Joseph P. Weir
    • 6
  • Ann M. Spungen
    • 1
    • 2
    • 3
  • William A. Bauman
    • 1
    • 2
    • 3
    • 7
  1. 1.Veterans AffairsMedical Center SCI and Medical ServicesBronxUSA
  2. 2.Spinal Cord Damage Research CenterUSA
  3. 3.Dept. of MedicineMount Sinai School of MedicineNew YorkUSA
  4. 4.Veterans AffairsMedical Center Spinal Cord Damage Research, Rm. 1E-02BronxUSA
  5. 5.Dept. of RehabilitationMedicine College of Physicians and Surgeons Columbia UniversityNew YorkUSA
  6. 6.Des Moines University-Osteopathic Medical CenterDes MoinesUSA
  7. 7.Dept. of RehabilitationMedicine Mount Sinai School of MedicineNew YorkUSA

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