Background: Complete Heart Block (CHB) is one of the most important cardiac event emergencies.The present study was achieved to evaluate the variable types of CHB, associated with congenital heart disease, predominantly clinical manifestation, complication, treatment, outcome and mortality rate.

 Materials and methods: In a retrospective overview, 54 children with CHB admitted in Rajaie Heart Hospital were studied between 1979-1981 and 1991-1999. Data were collected by multiple-purpose questionnaires and then analyzed with descriptive statistic methods.

 Results: Congenital, acquired- post surgical and non surgically CHB had been reported at about 63%, 26% and 11% of the cases, respectively. Meanwhile, acquired post surgical and congenital CHB were associated with congenital heart disease at 100% and 25% of cases respectively. Syncope and ECG findings were the most common manifested symptoms in

 congenital and acquired CHB. However, pacemaker malfunction and mortality rate were reported in 13% and 13% of the cases, respectively.

Conclusion: Since CHB is a cardiac emergency and the most common cause of death in newborn is CHB, primary cares and immediate pacemaker implantation seems to be vital.