Objective To investigate perioperative myocardial injury and cardiac function changes in children undergoing permanent pacemaker implantation. Methods The clinical data of children who underwent permanent pacemaker implantation for various types of bradycardia from November 2018 to October 2019 were reviewed. The blood troponin I (cTnI), creatine kinase (CK)-MB isoenzyme, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) of the children were compared before the pacemaker implantation operation, 1 day after and 1 week after the operation. The left ventricular end diastolic diameter (LVEDD) Z value and left ventricular ejection fraction (LVEF) by transthoracic echocardiography before and 1 week after the operation were compared. Results Twenty-one children ( 8 boys and 13 girls) were included, with an age of 8 . 0 ( 4 . 0 - 11 . 0 ) years and a weight of 26 . 1 ( 15 . 3 - 45 . 8 ) kg. Dual-chamber pacemakers were implanted in 15 cases and single-chamber pacing in 6 cases. There were statistically significant differences in the levels of cTnI and CK-MB in 21 children before, 1 day after and 1 week after pacemaker implantation (P<0 . 001). The levels of cTnI and CK-MB were the highest one day after operation, which were higher than those before and one week after operation, respectively, with statistical significance (P<0 . 05 ). The LVDD-Z and LVEF values of 21 children one week after pacemaker implantation were lower than those before implantation, and the difference was statistically significant (P<0.05 ). Conclusions Children with bradycardia may experience shortterm, mild and reversible myocardial damage after implantation of a permanent pacemaker, but it has a protective effect on heart function.