心肌挫伤后心功能障碍发病机制探讨

The Relationship Between Cardiac Dysfunction and The Caldum Station Alterations After Blunt Chest Trauma

目的 探讨心肌挫伤（MC）后心功能障碍与钙稳态改变之间的关系及其意义。方法 随机选取兔36只，分为6组：正常对照，伤后2h、4h、8h、12h、24h，每组6只。经右颈总动脉插管至左心室测左室压力。采用BIM-Ⅱ型生物撞击机致成MC模型。在上述时相点测定左室压力，并取动物心脏，测定心肌细胞内[Ca^2＋]i含量、游离钙调素和总钙调素活性的变化。结果 心脏收缩／舒张功能受到损害，左心室收缩功能在伤后4-6h恢复至伤前水平，舒张功能在伤后24h不能恢复至伤前水平；心肌细胞内[Ca2^＋]i含量和总钙调素活性升高（P〈0．05），游离钙调素活性降低（P〈0．05）。相关分析表明心肌细胞内[Ca^2＋]i含量升高和心脏收缩／舒张功能障碍呈明显相关（P〈0．05）。结论 MC后心脏收缩／舒张功能发生明显改变，心肌细胞钙稳态失调是引起心功能障碍的原因之一。

Objective To explore the changes and the significance of the hemodynamics after myocardial contusion（MC） in rabbits. Methods Using the model of MC with BIM - Ⅱ Bin - impactor in 36 rabbits to observe the changes of the hemodynamies and to detect the free calcium,frce calmodulin and total ealmodulin at pre- injury,2h,4h,Sh, 12h and 24h post- injury. Results The cardiac function were impaired. The systolic function of left ventricl was impaired and recovered during 4 - 6h after MC, the diastolic function of left ventricle was impaired but not recovered 24h after MC. The free calcium and the total calmodulin in myocardial cells was lower and reachced its peak 8h after MC（ P 〈 0.05） .There is remarkable corretations betweent eh free calcium in myocardial cells was higher 4h and reached its peak 8h post - MC （ P 〈 0.05）,and then decreased but also higher 24h post- MC than that of pre- MC（ P 〈 0.05）;the free calmodulin in myocardial cells was lower and reached its peak 8h after MC（ P 〈 0.05）.There is remarkable correlations between the free calcium in myocardial cells and LVEDP and- dp/dtmax with cardiac function. Conclusion The cardiac function is changed obviously after MC. The higher of the free calcium in myocardial cells may be one of the reasons of cardiac dysfunction after MC.