RESUMO
In complete heart block(CHB), there is a complete failure of the atrial impulse leading into a ventricular response, the atria and ventricles beat independently, with the latter having a slower rate. Approximately one-third of infants with congenital CHB have associated structural heart disease such as corrected transposition of the great arteries, single ventricle, and the heterotaxy syndrome. For those patients without associated anomalies in whom bradycardia causes heart failure unresponsive to drugs, a pacemaker is necessary. We report a case of congenital complete heart block showing a ventricular beat of 57 /min despite atrial beat of 125/min. The mother of the baby was asymptomatic but her serologic tests were positive for connective tissue disease. The patient had positive serologic tests for anti-Ro antibody and anti-La antibody but associated structural heart anomalies were not found. He remained well without signs and symptoms of heart failure and no treatment was required except 02 supply.