Abstract:

Objective  To investigate the protective effect of α-methylnorepinephrine on cardiac function of rabbits at early stage after cardiopulmonary resuscitation (CPR). Methods  A total of 30 rabbits were randomly divided into the control group (group A, n=10), epinephrine group (groups B, n=10), and α-methylnorepinephrine group (group C, n=10). The rabbit model of CPR (group B and C) was established by in vitro induced ventricular fibrillation. Rabbits of group B were given epinephrine and group C were given α-methylnorepinephrine during the course of CPR, respectively. Changes of hemodynamic and serum indexes were dynamically monitored before ventricular fibrillation and at each time point after CPR. The ultrastructure of myocardial tissue was observed by transmission electron microscope after CPR. Results  After spontaneous circulation was restored, rabbits of both groups B and C appeared cardiac dysfunction and indexes of cardiac function significant decreased (P<0.05). The slope of contraction velocity (peak+dp/dt) of group C was significantly higher than that of group B (P<0.05), but the difference between groups C and A was not statistically significant (P>0.05). The slope of vasodilation velocity (peak－dp/dt) of group C was significantly lower than that of group A (P<0.05). The BNP and cTnⅠ levels of group C were significantly lower than those of group B (P<0.05). Observation by the transmission electron microscope showed that the myocardial structure of groups C and A was similar. Compared with group B, the myocardial injury of group C was mild. Conclusion  The α-methylnorepinephrine can improve hemodynamic and serum indexes, alleviate myocardial injury, and protect the cardiac function at early stage after CPR.

Key words: cardiopulmonary resuscitation, myocardial dysfunction；α-methylnorepinephrine