The coronary blood flow and myocardial oxygen consumption during simple deep hypothermia
Satoh, A.
Masui. Japanese Journal of Anesthesiology 34(9): 1194-1202
1985
ISSN/ISBN: 0021-4892 PMID: 4087354 Document Number: 254523
The coronary circulation and myocardial oxygen consumption were investigated in 15 healthy adult mongrel dogs under simple deep hypothermia. The measurement of the parameters was made at the control state (around 36.degree. C), 30.degree. C, 25.degree. C and 20.degree. C during cooling and at 25.degree. C, 30.degree. C and 35.degree. C during rewarming. Coronary blood flow (circumflex branch) decreased proportionately as body temperature was reduced to 20.degree. C. It was 24% of the control value (25.6 .+-. 8.9 ml/min), which was the lowest value. But it rose to 138% of the control value at 35.degree. C during rewarming. Myocardial oxygen consumption (circumflex branch area) decreased proportionately as body temperature was reduced to 20.degree. C. It was 21% of the control value (2.45 .+-. 0.59 ml/min), which was the lowest value, and it nearly regained the control value at 35.degree. C during rewarming. During the whole course of hypothermic state, the rate of decline of myocardial oxygen consumption was more significant than that of coronary blood flow, and coronary A-VDO2 [arterio-venous oxygen pressure difference] was unchanged. From these results, it is demonstrated that under simple deep hypothermia myocardial oxygen demand decreases sufficiently for myocardial protection.