Congenital complete atrioventricular block. A pace in time saves lives (?).

The study by Balmer et al. in the present issue of Europace lends support to our clinical notion that early intervention is beneficial even to the young individual. The children in this study that received a pacemaker had signs and/or symptoms such as bradycardia, exercise intolerance, syncope or heart failure that were ameliorated by pacemaker implantation. Three patients received a pacemaker within the first month of life. The common experience that the prognosis is worse when congenital complete atrioventricular block (CCAVB) is associated with cardiac malformation was not confirmed in this study. Interestingly there was no difference in heart rate between symptomatic and asymptomatic children before pacemaker implantation. The clinical consequence is that the resting heart rate does not help in determining the right time for intervention. Their main conclusion is that pacemaker therapy reduces morbidity and mortality in children with CCAVB when compared with natural history data. This information is valuable but there is still room for argument about when to intervene. In their study all symptomatic children received a pacemaker whereas asymptomatic ones did not. But is there an asymptomatic child with CCAVB? Is the breastfed baby with CCAVB symptomatic if feeding time is somewhat prolonged? Is the 7-year-old with CCAVB symptomatic if he does not want to play soccer? Is the 13-year-old computer-enthusiast with CCAVB symptomatic? My point is that our tools to detect symptoms at present are too blunt. We really need to know when to treat the (?) asymptomatic child and what pacemaker mode to choose. There is evidence that when the patient has passed the mid-teens, pacemaker implantation reduces mortality and morbidity. Although symptoms and signs such as premature ventricular complexes, wide QRS escape rhythm, fatiguability and effort dyspnoea are poor indicators of future severe