Abstract: Objective　To observe and analyze the changes of left ventricular function after long-term left ventricular high lateral posterior wall epicardial pacing, and to explore the optimal location of epicardial electrode implantation. Methods　Clinical and echocardiography data before operation and at last follow-up in 56 children implanted left ventricular high lateral wall epicardial pacing electrode from November 2008 to August 2016 were retrospectively analyzed. The results of two ultrasound examinations were analyzed. Results　Among the 56 cases, 31 had postoperative bradyarrhymia, and 25 had congenital or myocarditis bradyarrhymia. The median age at the implantation was 3.25 years, and the median follow-up period was 1.63 years. Ultrasound examination showed that preoperative left ventricular ejection fraction (LVEF) and left atrial (LA) diameter were (66.39±9.96) % and (25.48±7.22) mm respectively, and LVEF and LA diameter at the last follow-up were (69.32±7.13) % and (23.44±6.29) mm respectively, and the differences were statistically significant (P<0.05). The left ventricular end diastolic diameter (LVDd) and left ventricular end systolic diameter (LVDs) Z scores were ?1.42 (?4.67~0.89) and 0.06 (?2.39~2.72) at last follow-up, which were significantly reduced compared with 0.16 (?1.31~2.83) and ?1.88 (-4.48~0.10) at preoperation, and differences were statistically significant (P<0.05). Conclusion　High lateral posterior wall pacing of left ventricle can effectively protect and improve left ventricular function. It is an ideal location for epicardial implantation of pacing electrode in pediatric treatment of bradyarrhythmia.

Key words: left ventricular function;　epicardium;　pacing therapy;　Z score