1. The effects of left ventricular repair (LVR) surgery for ischaemic or dilated cardiomyopathy are not fully understood. The development of a proper animal model will help to resolve this issue. 2. The ischaemic cardiomyopathy (ICM) model used was as follows. Twenty-six rats developed ICM with a large akinetic left ventricular (LV) area after ligation of the left anterior descending artery (LAD). Four weeks after surgery, 13 rats underwent LVR by placating the akinetic area (LVR group), while 13 underwent rethoracotomy alone (sham group). 3. The dilated cardiomyopathy (DCM) model is as follows. Six Dahl salt-sensitive (DS) rats were fed an 8% NaCl diet from the age of 9 weeks and developed DCM. These rats had LVR by plicating the LV area between the papillary muscle bases (LVR group), while other rats underwent rethoracotomy alone (sham group). 4. Before LAD ligation in the ICM model or starting the high-salt diet in the DCM model and just before and after LVR or sham surgery, LV dimensions were measured by echocardiography and the heart rate and systolic blood pressure were recorded by the tail-cuff method. 5. In the ICM model, all rats survived the second surgery, after which LV end-diastolic diameter (EDD) decreased, LV fractional shortening (FS) increased (both P < 0.001 vs sham) and heart rate increased (P < 0.05) in the LVR group. 6. In the DCM model, LV EDD decreased and LV FS increased (both P < 0.001) in the LVR group. 7. Both models developed LV dilatation, tolerated LVR and enable reproducible physiological evaluation of the LV. Because the rats survived thereafter, both models may provide a useful tool for various investigations.