The relationship between left ventricular functions and calcium station alterations after blunt chest trauma

Abstract

Objective To explore the changes and the significance of left ventricular functions after blunt chest trauma(BCT)in rabbits.Methods 36 rabbit models of BCT with BIM-Ⅱ Bio-impactor in were used to observe the changes of left ventricular functions and free calcium,free calmodulin and total calmodulin were detected at pre-injury,the 2nd,4th,8th,12th and 24th hour after injury.Results The cardiac function were impaired.The systolic functions of left ventricle were impaired and recovered during 4-12 hour after BCT.The diastolic functions of left ventricle were impaired but not recovered 24h after BCT.The free calcium and total calmodulin in myocardial cells were increased from the 4th hour,reached,peak at the 8th hour post-BCT(P＜0.01),and then decreased,but were still higher at the 24th hour post-BCT than that of pre-BCT(P＜0.05).The free calmodulin in myocardial cells was low and reached peak at the 8th hour after BCT(P＜0.01).There is remarkable positive correlation between free calcium in myocardial cells and LVEDP and dp/dtmax with cardiac function(P＜0.05,P＜0.01).Conclusion The cardiac function is obviously changed after BCT,especially the diastolic functions of left ventricle.The hish concentration of free calcium in myocardial ceils may be one of the reasons of cardiac dysfunction after BCT. Key words: Thoracic injuries; Myocytes,cardiac; Calcium; Ventrieular function