Parental electrocardiographic screening identifies a high degree of inheritance for congenital and childhood nonimmune isolated atrioventricular block.

BACKGROUND: The origin of congenital or childhood nonimmune isolated atrioventricular (AV) block remains unknown. We hypothesized that this conduction abnormality in the young may be a heritable disease. METHODS AND RESULTS: A multicenter retrospective study (13 French referral centers, from 1980-2009) included 141 children with AV block diagnosed in utero, at birth, or before 15 years of age without structural heart abnormalities and without maternal antibodies. Parents and matched control subjects were investigated for family history and for ECG screening. In parents, a family history of sudden death or progressive cardiac conduction defect was found in 1.4% and 11.1%, respectively. Screening ECGs from 130 parents (mean age 42.0 ± 6.8 years, 57 couples) were compared with those of 130 matched healthy control subjects. All parents were asymptomatic and in sinus rhythm, except for 1 with undetected complete AV block. Conduction abnormalities were more frequent in parents than in control subjects, found in 50.8% versus 4.6%, respectively (P<0.001). A long PR interval was found in 18.5% of the parents but never in control subjects (P<0.0001). Complete or incomplete right bundle-branch block was observed in 39.2% of the parents and 1.5% of the control subjects (P<0.0001). Complete or incomplete left bundle-branch block was found in 15.4% of the parents and 3.1% of the control subjects (P<0.0006). Estimated heritability for isolated conduction disturbances was 91% (95% confidence interval, 80%-100%). SCN5A mutation screening identified 2 mutations in 2 patients among 97 children. CONCLUSIONS: ECG screening in parents of children affected by idiopathic AV block revealed a high prevalence of conduction abnormalities. These results support the hypothesis of an inheritable trait in congenital and childhood nonimmune isolated AV block.

Congenital portocaval fistula associated with hepatopulmonary syndrome: ligation vs liver transplantation.

A 4-year-old boy underwent pulmonary testing for diagnosis of exercise-induced dyspnea and subsequent cyanosis. Findings demonstrated the presence of multiple pulmonary arteriovenous fistulas resulting in oxygen desaturation owing to shunting (PaO2, 44 mm Hg). Abdominal ultrasound, abdominal computer tomography, and mesenteric angiography revealed an extrahepatic portocaval fistula (PCF), absence of a patent portal vein, and no evidence of portal hypertension. Because these findings were consistent with hepatopulmonary syndrome (HPS), liver transplantation was initially considered. However, subsequent workup using cavofistulography revealed the presence of a hypoplastic portal vein that selective catheterization showed to be threadlike but patent. Based on this finding, a definitive diagnosis of a congenital PCF with hypoplasia of the portal vein (type 2 Abernethy malformation) was made and surgical ligation with transection of the fistula was performed at the age of 5. Treatment was successful without subsequent development of portal hypertension and pulmonary symptoms disappeared. Follow-up examination 4 years later showed that the boy was asymptomatic and that the intrahepatic portal system was patent with normal hepatopetal flow. This is the first reported case of HPS because of portal type 2 Abernethy malformation. Anatomical types of PCF and corresponding therapeutic options in case of HPS are discussed.