To observe the effects of Kangxian Yixin Decoction（抗纤益心方，KYD）on myocardial mitochondrial ridge and its structural proteins mitochondrial inner membrane ridge structure protein 10（Mic10），mitochondrial inner membrane ridge structure protein 60（Mic60）and mitochondrial inner membrane ridge structure protein 19（Mic19）in mice with dilatedcardiomyopathy（DCM），and explore the mechanism of protecting DCM mitochondrial ridge structure and improving mitochondrial energy metabolism.

According to random number table method，40 cTnTR141W transgenic DCM mice were divided into model group，KYD low-dose group，KYD medium-dose group，KYD high-dose group and captopril group，with 8 mice in each group，and 8 C57BL/6J mice in normal group.Left ventricular end-systolic diameter（LVESD），left ventricular end-diastolic diameter（LVEDD），ejection fraction（EF）and fraction shorting（FS）were detected by ultrasonography.Myocardial pathological morphology was observed by HE staining，and mitochondrial ultrastructure was observed by electron microscopy.Enzyme-linked immunosorbent assay（ELISA）was used to detect the contents of NT-proBNP and adenosine triphosphate（ATP）in serum of mice.The mRNA and protein expressions of Mic10，Mic60 and Mic19 were detected by Real-time PCR and Western blotting，respectively.

Compared with those in the normal group，in the model group，the levels of LVESD and LVEDD were increased，the levels of FS and EF were decreased（P<0.05），myocardial pathological injury was observed，apoptotic number was increased（P<0.01），NT-proBNP content was increased，ATP content was decreased（P<0.01），mitochondrial ridge structure was damaged and disordered.The mRNA and protein expressions of mitochondrial ridge structure proteins Mic10，Mic60 and Mic19 were decreased（P<0.01）. Compared with those in the model group，in the KYD group，the levels of LVESD and LVEDD were decreased，the levels of FS and EF were increased（P<0.05），the myocardial injury was alleviated，the NT-proBNP content was decreased（P<0.01），the apoptosis was decreased，the ATP content was increased（P<0.05），the mitochondrial ridge damage and arrangement disorder were improved and the mRNA and protein expressions of mitochondrial ridge structure proteins Mic10，Mic60 and Mic19 were increased（P<0.01）.

KYD can improve DCM mice mitochondrial ridge arrangement disorder，alleviate myocardial cell apoptosis，and improve cardiac function，which may be related to increasing the expression of mitochondrial ridge structural proteins Mic10，Mic60 and Mic19 and improving mitochondrial energy metabolism.