|
|
||||||||
Division of Pediatric Critical Care, Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon 97201
We hypothesized that acute brain injury results in decreased
heart rate (HR) variability and baroreflex sensitivity indicative of
uncoupling of the autonomic and cardiovascular systems and that the
degree of uncoupling should be proportional to the degree of
neurological injury. We used HR and blood pressure (BP) power spectral
analysis to measure neuroautonomic regulation of HR and BP and the
transfer function magnitude (TF) between BP and HR as a measure of
baroreflex modulation of HR. In 24 brain-injured patients
[anoxic/ischemic injury (n = 7),
multiple trauma (n = 6), head trauma
(n = 5), central nervous system
infection (n = 4), and intracranial
hemorrhage (n = 2)],
neurological injury and survival was associated with low-frequency
(0.01-0.15 Hz) HR and BP power and TF. Brain-dead patients showed
decreased low-frequency HR power [0.51 ± 0.36 (SE) vs. 2.54 ± 0.14 beats/min2,
P = 0.03] and TF [0.61 ± 0.16 (SE) vs. 1.29 ± 0.07 beats · min
1 · mmHg
1,
P = 0.05] compared with
non-brain-dead patients. We conclude that
1) severity of neurological injury
and outcome are inversely associated with HR and BP variability and
2) there is direct evidence for
cardiovascular and autonomic uncoupling in acute brain injury with
complete uncoupling during brain death.
variability; power spectral analysis; transfer function magnitude; brain death
This article has been cited by other articles:
![]() |
A. Van de Louw, C. Medigue, Y. Papelier, and F. Cottin Breathing cardiovascular variability and baroreflex in mechanically ventilated patients Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2008; 295(6): R1934 - R1940. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Gericke, P. Martinka, I. Nazarenko, P. B. Persson, and A. Patzak Impact of {alpha}1-adrenoceptor expression on contractile properties of vascular smooth muscle cells Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1215 - R1221. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Lanfranchi and V. K Somers Arterial baroreflex function and cardiovascular variability: interactions and implications Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2002; 283(4): R815 - R826. [Abstract] [Full Text] [PDF] |
||||
![]() |
F Conci, M Di Rienzo, and P Castiglioni Blood pressure and heart rate variability and baroreflex sensitivity before and after brain death J. Neurol. Neurosurg. Psychiatry, November 1, 2001; 71(5): 621 - 631. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |