Objective To evaluate the effects of transcatheter renal sympathetic denervation (RSD) on the cardiac systolic function of dogs with pulmonary arterial hypertension(PAH)using two-dimensional speckle tracking imaging (2D-STI).Methods Twenty two dogs were divided in to three groups:control group (n=7),PAH group (n =8),PAH+RSD group(n =7).Pulmonary artery hypertension models were made by monocrotaline injection in PAH group and PAH+RSD group,while bilateral renal artery sympathetic nerve were also ablated in PAH+RSD group.Meanwhile,sham operation treatment were made in the control group and PAH group.The changes of blood pressure and cardiac indicies of ultrasound were observed before and after 8 weeks respectively.Then the left ventricular(LV)lateral strain,septal strain (IVS LS)and right ventricular(RV)strain were calculated.In the apical 4-chamber view,time from QRS onset to peak systolic strain in each the six segments of the LV and RV were measured and standard deviation of the time to peak longitudinal strain of six segments (LVTsl-6SD and RVTsl-6SD)were calculated.LV twist degree were obtained from LV rotation curve in basal and apical short-axis planes. Results After 8 weeks,there was no difference in the mean strain of LV lateral wall among the three groups,while the mean strain of RV lateral wall and septal were higher in PAH+RSD group than the PAH group [(18.91±0.86)% % vs 16.34±1.36)%,P <0.001;(18.39±1.03)% vs (17.02±1.00)%,P <0.001,respectively].Compared with PAH group,LVTsl-6SD and RVTsl-6SD of PAH + RSD group decreased significantly [(25.45±3.59)ms vs (40.40±2.83)ms,P <0.001;(34.16±2.81)ms vs (51.98± 3.64)ms,P <0.001,respectively].The LV twist degree of PAH+RSD group increased significantly[(10.47± 0.73)°vs (8.46±1.06)°,P <0.001].Conclusions RSD can reduce the influence of pulmonary artery hypertension on cardiac systolic function.