[Isolated congenital complete atrio-ventricular block]

The objective of this work was to study the long term evolution of a retrospective series of 54 patients affected with congenital isolated complete atrio-ventricular block (CAVB) and to analyse the value of the different methods used for surveillance. Our series included 54 patients affected with isolated CAVB, without associated cardiopathy, diagnosed at an average age of 5.3 +/- 5.5 years, of which 9 were in utero. The average duration of follow up was 14.5 +/- 9.6 years. During the evolution, a cardiac stimulator was placed in 41 patients (76%) at a relatively late average age of 13.3 +/- 9 years, significantly lower for CAVB diagnosed before the age of 1 year (9.6 +/- 7.4 years) than for those diagnosed after the age of 1 year (16.2 +/- 9.2 years) (p < 0.02). The approach was endocavitary in 39 cases and epicardial in 2 cases. The only 2 deaths in our series (4%) concerned 2 patients of 18 and 26 years already fitted with a stimulator. Three patients progressed to severe dilated cardiomyopathy despite implantation of a stimulator. The decisive arguments for implantation of a PM were clinical (11 patients), Holter ECG (25 patients), stress test (17 patients), electrophysiological investigation (5 patients), echocardiography (3 patients) and surgical intervention (2 patients). In conclusion, our study confirms the good prognosis of isolated congenital complete atrio-ventricular block, but underlines the possible progression in rare cases in spite of stimulation towards dilated cardiomyopathy for which the aetiology remains uncertain. Three quarters of the patients required a stimulator at a somewhat late age.