AimTo confirm the effects of left ventricular hypertrophy reversed by loosening abdominal aortic banding, and observe the changes of cardiac morphology, myocardial collagen volume fraction (CVF) and myocardial apoptotic index (AI).Methods75 SD rats were randomly divided into the normal group (N group, n=15), abdominal aortic banding group (AAB group, n=30) and loosening abdominal aortic banding group (LAAB group, n=30).AAB and LAAB group received the first operation of narrowing the abdominal aorta to establish left ventricular hypertrophy model in rat.After 5 weeks, the LAAB group received the second operation of removing the abdominal aorta banding.After 5 weeks of the first operation and after 4 weeks of the second operation, heart mass index (HMI), left ventricular mass index (LVMI), interventricular septum thickness of end-diastolic (IVSTd), left ventricular posterior wall thickness of end-diastolic (LVPWTd), myocardial CVF and myocardial AI of three groups of rats were observed by general observation, ultrasonic cardiogram, myocardial Masson staining, myocardial tunel staining.ResultsHMI, LVMI, IVSTd, LVPWTd, myocardial CVF and myocardial AI were significantly increased in AAB group.After 4 weeks of removing the abdominal aorta banding, HMI, LVMI, IVSTd, LVPWTd, myocardial CVF and myocardial AI of LAAB group were significantly decreased compared with AAB group, but still higher than N group.ConclusionLoosening abdominal aortic banding could partly reverse the left ventricular hypertrophy.