Objective:Objective:To observe the effects and dose-effect relationship of "ethanol extract from Polygonatum Odoratum" on Hemodynamics in Rats of Heart Failure Following Myocardial Infarction.Methods:Seventy healthy Sprague-Dawley rats were divived randomly into sham group

model group

large dosage of "ethanol extract from Polygonatum Odoratum" group

moderate dosage of "ethanol extract from Polygonatum Odoratum" group

small dosage of "ethanol extract from Polygonatum Odoratum" group.After successful model duplication

rats in different dosage of "ethanol extract from Polygonatum Odoratum" groups were treated with intravenous injection of 6 g/kg

3 g/kg

0.3 g/kg distinctly

while rats in sham group or model group received 6 ml/kg saline.The heart rate（HR）

left ventricular systolic pressure（LVSP）

left ventricular diastolic pressure（LVDP）

maximum rise speed of left ventricular pressure（+dp/dtmax）

maximum drop speed of left ventricular pressure（-dp/dtmax）were measured at different time points（before injection and 5

10

20

30 minutes after injection）and comparatively analyed.Result:The HR decreased at 5 minutes in large dosage group and model group

the LVSP was lower

the +dp/dtmax and-dp/dtmax were slower

the LVDP increased at the same time

all these parameter went back to normal at 20 and 30 minutes points

the small dosage group was found changes in these parameters at 10 minutes point except HR.Conclusion:"ethanol extract from Polygonatum Odoratum" has negative inotropic and negative chronotropic action in CHF rats.These two actions have dose-effect relationship.