Short-and long-term outcome of children with congenital complete heart block diagnosed in utero or as a newborn

Objectives. Few data are available in the literature regarding the long-term outcome of newborns with congenital complete heart block (CHB). The aims of this retrospective study were to assess neonatal morbidity and mortality, incidences of dilated cardiomyopathy (DCM), and associated heart defects, and to establish prenatal and postnatal factors that might predict adverse outcome in children with CHB. Design and Setting. The cohort includes 91 infants with CHB diagnosed in 5 tertiary centers in Finland between 1950 and 1998. Patients. Maternal connective tissue disease was evident in 89% of the patients. At birth, the median gestational age was 37.1 weeks, and the median weight was 2969 g. Of the 91 infants, 60 (66%) were girls and 7 (8%) were twins. Results. Incidences of perinatal morbidity and mortality were 58% and 7%, respectively. The total mortality of CHB was 16%; 11 of 15 (73%) died during the first 12 months. Cumulative probability of survival at 10 years old was 82%. Pacing as a newborn was indicated in 48 of 90 cases (53%), and 36 received pacemakers at older ages. Cardiac defects not causally related to CHB were found in 38 of 90 patients (42%), of whom 22 were operated on. DCM was found in 21 (23%), of whom 13 died. During the follow-up, among 75 survivors with a median age of 9 years, 54 (72%) are free from symptoms. Poor outcome defined as clinically or pathologically evident congestive DCM was associated with intrauterine hydrops, low fetal and neonatal heart rate, low birth weight, male sex, and neonatal problems attributable to prematurity or neonatal lupus. Conclusions. Despite early pacing, CHB carries high mortality during the first 12 months of life. High incidences of DCM and associated heart defects indicate close echocardiographic monitoring of all children with CHB.