Effects of Dexmedetomidine Pretreatment, Posttreatment, and Whole-Course Pumping on Myocardial Damage during Cardiac Valve Replacement.

To compare the effects of dexmedetomidine (DEX) pretreatment, posttreatment, and whole-course pumping on myocardial protection during cardiac valve replacement.One hundred and twenty patients undergoing cardiac valve replacement were randomly divided into the follow groups: DEX pretreatment (D1 group), DEX posttreatment (D2 group), DEX whole-course pumping (D3 group), and Control (C group). The concentrations of cardiac troponin I (cTnI), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), rate of spontaneous heart rebound after aortic opening, time to heart rebound, incidence of arrhythmia, and use of sufentanil and vasoactive drugs were recorded.Compared with group C, the concentrations of cTnI, MDA, and TNF-α in the D1, D2, and D3 groups were lower, especially in the latter. The time to heart rebound was prolonged in all three groups (P < 0.05). The rate of automatic rebound was increased (P < 0.05) while the incidence of arrhythmia was decreased (P < 0.05) in all groups compared with group C. Group D3 had the highest rate of automatic rebound and the lowest incidence of arrhythmia. Compared with groups C and D2, the use of sufentanil and dopamine was lower in groups D1 and D3 (P < 0.05), especially in the latter.During cardiac valve replacement, DEX pretreatment, posttreatment, and whole-course pumping could have myocardial protective effects. The latter showed better effects.