Characterization of energy metabolism and blood flow distribution in myocardial ischemia in hemorrhagic shock

Koji Miyazaki, Shingo Hori, Sohshin Inoue, Takeshi Adachi, Motoaki Bessho, Ichiro Kuwahira, Hidezo Mori, Hiroe Nakazawa, Naoki Aikawa, Satoshi Ogawa

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

To characterize the mechanisms for myocardial ischemia induced by hemorrhagic shock, 29 dogs were subjected to hemorrhage at a mean aortic pressure (MAoP) of 30-60 mmHg. After 10 min of hemorrhage, the beating hearts were rapidly cross sectioned and freeze clamped to visualize the two- dimensional distribution of myocardial ischemia with NADH fluorescence (NADH- F) in 22 dogs. NADH-F was developed at an MAoP of 40 mmHg or less and involved both the subendocardial half and the subepicardial half of the left ventricle [34 ± 14 vs. 20 ± 14% (P < 0.05) and 65 ± 16 vs. 52 ± 15% (not significant) of the cross-sectional area of the left ventricular slice at MAoP levels of 40 and 30 mmHg, respectively]. Magnified NADH-F photography demonstrated heterogeneously distributed microischemic lesions with a columnar shape (mode of short-axis length, 60-80 μm). NADH-F-guided microsamplings revealed higher NADH and lactate concentrations in a positive NADH-F area than those in a negative NADH-F area. The ratio of endocardial to epicardial blood flow was maintained at a relatively high level (1.07 ± 0.07 and 0.88 ± 0.07 at MAoP levels of 40 and 30 mmHg, respectively; n = 7 dogs), and the reactive hyperemia was preserved as well. In conclusion, myocardial ischemia in early hemorrhagic shock was characterized by minimal transmural heterogeneity and marked heterogeneity between contiguous small regions.

Original languageEnglish
Pages (from-to)H600-H607
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume273
Issue number2 42-2
DOIs
Publication statusPublished - 1997

Keywords

  • Anaerobic metabolism
  • Coronary circulation
  • Coronary reserve
  • Reduced nicotinamide adenine dinucleotide fluorescence
  • Regional flow

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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