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Mild hypothermia reduces cardiac post-ischemic reactive hyperemia

Olivecrona, Göran LU ; Götberg, Matthias LU ; Harnek, Jan LU ; vanderPals, Jesper LU and Erlinge, David LU (2007) In BMC Cardiovascular Disorders 7(5).
Abstract
BACKGROUND: In experimentally induced myocardial infarction, mild hypothermia (33-35 degrees C) is beneficial if applied prior to ischemia or reperfusion. Hypothermia, when applied after reperfusion seems to confer little or no benefit. The mechanism by which hypothermia exerts its cell-protective effect during cardiac ischemia remains unclear. It has been hypothesized that hypothermia reduces the reperfusion damage; the additional damage incurred upon the myocardium during reperfusion. Reperfusion results in a massive increase in blood flow, reactive hyperemia, which may contribute to reperfusion damage. We postulated that hypothermia could attenuate the post-ischemic reactive hyperemia. METHODS: Sixteen 25-30 kg pigs, in a closed chest... (More)
BACKGROUND: In experimentally induced myocardial infarction, mild hypothermia (33-35 degrees C) is beneficial if applied prior to ischemia or reperfusion. Hypothermia, when applied after reperfusion seems to confer little or no benefit. The mechanism by which hypothermia exerts its cell-protective effect during cardiac ischemia remains unclear. It has been hypothesized that hypothermia reduces the reperfusion damage; the additional damage incurred upon the myocardium during reperfusion. Reperfusion results in a massive increase in blood flow, reactive hyperemia, which may contribute to reperfusion damage. We postulated that hypothermia could attenuate the post-ischemic reactive hyperemia. METHODS: Sixteen 25-30 kg pigs, in a closed chest model, were anesthetized and temperature was established in all pigs at 37 degrees C using an intravascular cooling catheter. The 16 pigs were then randomized to hypothermia (34 degrees C) or control (37 degrees C). The left main coronary artery was then catheterized with a PCI guiding catheter. A Doppler flow wire was placed in the mid part of the LAD and a PCI balloon was then positioned proximal to the Doppler wire but distal to the first diagonal branch. The LAD was then occluded for ten minutes in all pigs. Coronary blood flow was measured before, during and after ischemia/reperfusion. RESULTS: The peak flow seen during post-ischemic reactive hyperemia (during the first minutes of reperfusion) was significantly reduced by 43 % (p < 0.01) in hypothermic pigs compared to controls. CONCLUSION: Mild hypothermia significantly reduces post-ischemic hyperemia in a closed chest pig model. The reduction of reactive hyperemia during reperfusion may have an impact on cardiac reperfusion injury. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
BMC Cardiovascular Disorders
volume
7
issue
5
publisher
BioMed Central
external identifiers
  • pmid:17324251
  • scopus:33847794603
ISSN
1471-2261
DOI
10.1186/1471-2261-7-5
language
English
LU publication?
yes
id
ded2fc15-c27b-465a-9981-cfe9c2be9882 (old id 1140030)
date added to LUP
2008-08-21 11:35:44
date last changed
2017-07-30 04:34:08
@article{ded2fc15-c27b-465a-9981-cfe9c2be9882,
  abstract     = {BACKGROUND: In experimentally induced myocardial infarction, mild hypothermia (33-35 degrees C) is beneficial if applied prior to ischemia or reperfusion. Hypothermia, when applied after reperfusion seems to confer little or no benefit. The mechanism by which hypothermia exerts its cell-protective effect during cardiac ischemia remains unclear. It has been hypothesized that hypothermia reduces the reperfusion damage; the additional damage incurred upon the myocardium during reperfusion. Reperfusion results in a massive increase in blood flow, reactive hyperemia, which may contribute to reperfusion damage. We postulated that hypothermia could attenuate the post-ischemic reactive hyperemia. METHODS: Sixteen 25-30 kg pigs, in a closed chest model, were anesthetized and temperature was established in all pigs at 37 degrees C using an intravascular cooling catheter. The 16 pigs were then randomized to hypothermia (34 degrees C) or control (37 degrees C). The left main coronary artery was then catheterized with a PCI guiding catheter. A Doppler flow wire was placed in the mid part of the LAD and a PCI balloon was then positioned proximal to the Doppler wire but distal to the first diagonal branch. The LAD was then occluded for ten minutes in all pigs. Coronary blood flow was measured before, during and after ischemia/reperfusion. RESULTS: The peak flow seen during post-ischemic reactive hyperemia (during the first minutes of reperfusion) was significantly reduced by 43 % (p &lt; 0.01) in hypothermic pigs compared to controls. CONCLUSION: Mild hypothermia significantly reduces post-ischemic hyperemia in a closed chest pig model. The reduction of reactive hyperemia during reperfusion may have an impact on cardiac reperfusion injury.},
  articleno    = {(9 s)},
  author       = {Olivecrona, Göran and Götberg, Matthias and Harnek, Jan and vanderPals, Jesper and Erlinge, David},
  issn         = {1471-2261},
  language     = {eng},
  number       = {5},
  publisher    = {BioMed Central},
  series       = {BMC Cardiovascular Disorders},
  title        = {Mild hypothermia reduces cardiac post-ischemic reactive hyperemia},
  url          = {http://dx.doi.org/10.1186/1471-2261-7-5},
  volume       = {7},
  year         = {2007},
}