Abstract: To investigate the action of againtheart injury by preacaution intravenous cyclic adenosine monophosphate(cAMP)pro injection.39 hospitalized patients with intracardiac catheterization were selected.These patients were radomized divided into 3 groups.There is 9 cases in the group of using cAMP pro injection before intracardiac catheterizatio treatment(before group),15 acses after the operation(after group),and 13 acses is not use cAMP pro injection(control group).The way of giving the medicine is intravenous cAMP pro injection for 3 days.We observed heart rate,blood pressure,AST,CK,CK-MB and LDH before and after 0.5,6,12,24,48 hours.There is no statistics in 3 groups before and after operation(P>0.05).The cardiac muscle enzyme of AST、CK、CK-MB、LDH is lower in before group to another groups(P<0.05).There is no statistics in after group and control group(P>0.05).Cyclic adenosine monophosphate could imporve he metabolism of cardiac cellular and againstheart injury.