AUTHOR=Wei Lihui , Zeng Decai , Huang Liuliu , Luo Xiangjie , Wu Ji TITLE=A case report of delayed persistent third-degree atrioventricular block 7 years after eccentric umbrella occlusion of a perimembranous ventricular septal defect in infancy JOURNAL=Frontiers in Pediatrics VOLUME=Volume 13 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2025.1591928 DOI=10.3389/fped.2025.1591928 ISSN=2296-2360 ABSTRACT=This article reports an 8-year-old female patient who underwent trans-thoracic small-incision interventional Pm-VSD occlusion with an eccentric umbrella (defect diameter 10 mm, occluder waist diameter 12 mm) at 4 months of age (July 2017). Seven years after the operation (October 2024), she gradually developed third-degree atrioventricular block. Despite the removal of the occluder and ventricular septal defect repair combined with steroid pulse therapy, the conduction abnormality persisted. This case, with a 7 - year disease course evolution, provides in - depth insights into the development process of delayed complete atrioventricular block (CAVB) following eccentric umbrella occlusion in infancy and early childhood, particularly for high - risk patients with occlusion adjacent to the conduction system. It also suggests the significance of electrocardiogram monitoring for over 5 years post - operation in such high - risk patients.