TY - JOUR
T1 - Characterization of energy metabolism and blood flow distribution in myocardial ischemia in hemorrhagic shock
AU - Miyazaki, Koji
AU - Hori, Shingo
AU - Inoue, Sohshin
AU - Adachi, Takeshi
AU - Bessho, Motoaki
AU - Kuwahira, Ichiro
AU - Mori, Hidezo
AU - Nakazawa, Hiroe
AU - Aikawa, Naoki
AU - Ogawa, Satoshi
PY - 1997
Y1 - 1997
N2 - 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.
AB - 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.
KW - Anaerobic metabolism
KW - Coronary circulation
KW - Coronary reserve
KW - Reduced nicotinamide adenine dinucleotide fluorescence
KW - Regional flow
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M3 - Article
C2 - 9277474
SN - 0363-6135
VL - 273
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 2 42-2
ER -