Objective To explore the potential mechanism of Huangqi [Astragali radix

黄芪] and Dangshen[Codonopsis radix

党参] in treating heart failure. Methods Forty-eight C57BL/6J mice were randomized into sham operation group

model group

Huangqi group and Dangshen group

with 12 mice in each group. The heart failure model was built by shrinking thoracic aorta in each group except the sham operation group. Three days later

Huangqi group was given 12 g/（ kg·d） of Huangqi granules

while Dangshen group was given 6 g/（ kg·d） of Dangshen granules

and the sham operation group and the model group were administered 20 ml/（ kg · d） of normal saline. All groups were treated by gavage for 4 weeks. The cardiac function of mice in each group was detected

and the systolic function indexes included ejection fraction（ EF）

left ventricular short axis fraction shortening（ FS）

diastolic function indexes including the early peak wave（ E） and late filling wave（ Ea） around the mitral valve as well as the E/Ea were calculated. Cardiomyocytes were separated

and calcium transient peak and fall time were recorded by laser confocal microscopy. Results Compared with those in the sham operation group

EF

FS and Ea decreased significantly

while E/Ea increased significantly

the calcium transient peak decreased

and the fall time prolonged in the model group（ P < 0. 01）. Compared with those in the model group

EF

FS

E and Ea increased

E/Ea decreased

and calcium transient fall time was shorter in the Huangqi group; while EF

FS and calcium transient peak increased and the calcium transient fall time decreased in Dangshen group（ P < 0. 05 or P < 0. 01）. Conclusion Dangshen and Huangqi could increase the calcium transient peak and shorten the fall time in myocardial cells of heart failure mice

which may be one of the mechanisms of them in treating heart failure.