Objective To explore the impact of Dazhu Hongjingtian [Rhodiola Kirilowii Regel]（ 大株红景天）injection on myocardial damage in patients with acute severe carbon monoxide poisoning（ ASCOP） and the possible mechanism. Methods One hundred and four ASCOP patients were randomized into a control group and a treatment group

with 52 cases in each group. Both groups were given western medicine routine therapy. In addition to that

the treatment group was given 10 ml of Dazhu Hongjingtian injection by intravenous drip

once every day. Both groups were treated for 2 weeks. Changes of serum levels of heart fatty acid binding protein（ H-FABP） and myoglobin（ Myo） were detected in both groups before treatment

as well as at the 6th hour and on the 14 th day of the treatment.Blood levels of nitric oxide（ NO）

nitricoxide synthase（ NOS） and inducible nitric oxide synthase（ iNOS） were detected before and after treatment. The scores of mini-mental state examination（ MMSE） and the changes of left ventricular ejection fraction（ LVEF） level were recorded. The incidence of major adverse cardiac events was observed.The correlation between serum levels of H-FABP and LVEF of patients on admission was analyzed by Pearson correlation test. Results The serum levels of H-FABP and LVEF in both groups at the 6th hour of treatment were higher than those before treatment

while those in the treatment group were lower than those in the control group（ P <0. 05）. On the 14th day of treatment

the serum levels of H-FABP and LVEF in both groups were lower than those before treatment and at the 6th hour of treatment（ P < 0. 05）. After treatment

blood levels of NO

NOS and iNOS decreased（ P < 0. 05）

and LVEF level and MMSE scores increased in both groups. After treatment

MMSE scores in the treatment group were superior to those in the control group（ P < 0. 05）. The incidence of major adverse cardiac events in the treatment group was lower than that in the control group（ P < 0. 05）. Serum level of H-FABP of 104 patients on admission was negatively related to LVEF（ r =-0. 235

P = 0. 017）. Conclusion Dazhu Hongjingtian injection might reduce ASCOP myocardial damage and adverse cardiac events and improve heart function

which might relate to decreasing the blood levels of H-FABP

Myo

NO

NOS and iNOS.