Sinus node function in children with congenital complete atrioventricular block

Aims: Children with congenital complete atrioventricular block (CCAVB) often need pacemaker therapy. In these children, it may be preferable to use single-lead VDD pacing, but for VDD pacing a normal sinus node function is required. Our aim was to study sinus node function in children with CCAVB. Methods and results: We longitudinally evaluated sinus rate in 36 children with CCAVB and normal anatomy of the heart. The rate of sinus rhythm on a 12-lead ECG, in Holter recordings, and exercise tests were evaluated at regular intervals. Age at the first visit of the children was 2.5 ± 3.3 years (mean ± SD). Follow-up was 10.6 ± 7.3 years. The rate of sinus rhythm on a 12-lead ECG was at every age within the normal values for age (e.g. 0-1 year: 153 ± 24 bpm, and 17-18 years: 76 ± 4 bpm). Lowest and highest sinus rates in the Holter recordings were normal. During exercise, mean sinus rate in the total group of children increased from 92 ± 8 at rest to 171 ± 9 bpm at maximal exercise. Conclusion: We conclude that sinus node function is normal in children with CCAVB. Because of the normal increase in sinus rate during exercise, a single-lead VDD pacemaker can be safely implanted in these children.