Expression And Significance Of Heat Shock Protein 70(HSP70) Of Atrial Myocytes In Beating Heart Mitral Valve Replacement

Objective:To investigate the expression of atrial myocytes HSP70 of patients with mitral valve replacement in beating heart.Methods:Patients were divided into two groups:16 patients in controlled group (aorta crossclamped and mild hypothermia)and 14 ones in experimental group (aorta unclamped and moderate hypothermia).Samples of right atrial myoctyes were respectively taken before CPB and while stop CPB.The expression of atrial myocytes HSP70 was analyzed by immuntyhistochemistry.Results:Atrial myocytes HSP70 expression of experimental group increased significantly after CPB(P＜0.01)while HSP expression of controlled group showed no significant differences.Whereas HSP expression of experimental group was higher than that of controlled group after CPB(P＜0.01).Conclusion:HSP70 expression of atrial myocytes in beating heart MVR is higher than that in stop-beating heart MVR,which indicates operation on beating heart may place a premium on higher HSP expression.The mechanism may relevant to the less sensitive HSP expression in stop-beating heart with its inhibiting myocytes or less myocardial injury in beating heart during operation for its similar normal physical process compared with traditional stop-beating heart.