Assessment of myocardial oxygen metabolism and its performance during progressive hypoxemia.

评估进行性低氧血症期间的心肌氧代谢及其表现。

• 批准号: 08671756
• 负责人: ODA Toshiyuki
• 金额: $ 1.34万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08671756/
• 关键词: Systemic oxygen metabolism; Myocardial oxygen metabolism; Myocardial contractility; Left ventricular pressure-volume relations (LVPVR); End-systomic pressure-volume relations (ESPVR); End-systolic elastance; 体組織酸素代謝; 左室左-容積関係; 心筋収縮性; 低酸素症

The relationships between cardiac function and both systemic and myocardial oxygen metabolism were investigated during progressive hypoxemia.Sutudy 1 : relationship between cardiac function and systemic oxygen metabolismNine pigs were subjected to progressive hypoxemia by sequential reduction of inspired oxygen concentration (F_<IO2>) from 0.21 to 0.10. The reduction of an oxygen content of arterial blood (Cao_2) followed a significant increase in cardiac output (CO) at an F_<IO2> of 0.13. The increase in CO showed a peak value at an F_<IO2> of 0.11. Left ventricular end-systolic elastance (Ees), a measure of myocardial contractility, showed the peak value at an F_<IO2> of 0.13, then it turned to decline. The ventriculoarterial coupling, determined by the ratio of arterial elastance to Ees (Ea/Ees), was well-balanced at an F_<IO2> of 0.13. These observations suggest that the myocardial contractility may reduce even if CO reveals compensatory increase against the reduction of oxygen del … More ivery (D_<o2>) during progressive hypoxemia.Study 2 : Relationship between cardiac function and myocardial oxygen metabolismThe relationship between cardiac function and myocardial oxygen metabolism were investigated in three pigs subjected to progressive hypoxemia by sequential reduction of F_<IO2> from 0.21 to 0.10. The coronary blood flow. showed a maximum value at an F_<IO2> of 0.11, then decrased. The myocardial D_<o2> MD_<02> reached to maximum at an F_<IO2> of 0.13, then decreased below control (F_<IO2> 0.21) level at an F_<IO2> of 0.11. The changes in Ees shown in study 1 was coincided with the changes in MD_<o2> suggesting that the myocardial contratility may be changing dependent to MD_<o2>.In summary, during progressive hypoxemia it is suggested that myocardial contractility reduces when the cardiac output is still increasing to compensate the reduction of Do_2, and that the myocardial contractility is changing dependent to MDo_2. Accordingly, in the treatment of hypoxemia, it will be necessary to adjust systemic oxygenation with myocardial oxygen metabolism assessing the myocardial contractility itself, e.g.Ees. Less

对进行性低氧血症时心功能与全身和心肌氧代谢的关系进行了研究。研究1：心功能与全身氧代谢的关系9只猪，通过将吸入氧浓度(F&lt；IO2&Gt；)从0.21依次降低到0.10，造成进行性低氧血症。动脉血氧含量(CaO_2)降低后，心输出量(CO)显著增加，F_lt；IO2&Gt；为0.13。CO的增加在F&lt；IO2&Gt；为0.11时出现峰值。左心室收缩末期弹性(EES)是衡量心肌收缩能力的指标，在F_&lt；IO2&Gt；为0.13时达到峰值，然后逐渐下降。由动脉弹性与EES的比率(Ea/Ees)确定的脑室-动脉耦合在F_&lt；IO2&Gt；为0.13时是很平衡的。这些观察结果表明，即使CO表现出相对于氧Del…降低的代偿性增加，心肌收缩能力也可能降低研究2：心功能与心肌氧代谢的关系通过将F&lt；O2&gt；从0.21依次降低至0.10，对3只进行性低氧血症猪的心功能与心肌氧代谢的关系进行了研究。冠脉血流量。在F_&lt；IO2&gt；时显示最大值0.11，然后下降。心肌D_&lt；O2&gt；MD_&lt；02&gt；在F_&lt；IO2&gt；为0.13时达到最大值，然后在F_&lt；IO2&gt；为0.11时降至低于对照组(F_&lt；IO2&gt；0.21)。研究1显示的EES的变化与MDO2和GT的变化一致，提示心肌的收缩能力可能依赖于MD；；O2和Gt；。综上所述，进行性低氧血症时，心肌收缩能力下降时，心输出量仍在增加，以补偿DO_2的减少，心肌收缩能力的改变依赖于MDO_2。因此，在低氧血症的治疗中，有必要通过评估心肌收缩能力本身来调节全身氧合，如EES。较少