The application of intracardiac his bundle Recording and atrial pacing in the diagnosis of AV block in children

7 cases of AV block in children were reported.All patients underwent intracardiac His bundle recording and one of them the block was induced by incremental atrial pacing.There were 3 cases of intranodal second degree type I block,one case of infra-His 2:Ⅰ block,2 cases of intranodal third degree block and one case of infra-His third degree block.Their basic cardiac diseases were:myocarditis or its sequalae—5 cases,familial QT prolongation syndrome—one case and congenital AV block one case. It is ismportant to determine the site of block precisely in patients of AV conduction defect. The convention ECG demonstration the AV block alone is not sufficient to locate block site accurately,while His bundle recording can fulfill this readily.Although intracardiac recording is invasive,the Seldinder’s percutaneous procedure is easy to manipulate.In order to manage the children patients with AV block better,we consider its application warranted in pediatric cardiology.