Bloqueo auriculoventricular fetal completo: enfoque diagnóstico y terapéutico; reporte de caso en Bogotá, Colombia y revisión de la literatura

Objective: To report a case of complete congenital atrioventricular block and to review the literatura on diagnosis and treatment. Materials and methods: Case report of a 27-year-old pregnant woman who came to a high complexity general hospital with a 33-week singleton gestation and a diagnosis of complete atrioventricular block and secondary dilated cardiomyopathy. Response to initial prenatal management with beta-mimetic therapy was poor, and the woman had to be taken to Cesarean section. The newborn required implantation of a ventricular pacemaker on the first day of life, with excellent results at 1-year follow-up. A review of the literature published in Medline, Lilacs and SciELO databases was conducted using the terms “foetal complete atrioventricular block”, “congenital complete heart block,” limited to articles published between 2000 and 2016 in Spanish and English. Results: Overall, 21 publications were retrieved: seven case reports, ten reviews of the literatura and four cohort studies. Diagnosis is based on the foetal echocardiographic scan to determine the PR interval and the atrioventricular ratio, and to detect intracardiac abnormalities, including valvular regurgitation, myocardial/valvular hyperechogenicity, endocardial fibroelastosis, premature atrial contractions, and pericardial effusion. In terms of prenatal treatment, corticosteroids and beta-mimetics are the most widely used medications. Treatment of severe neonatal refractory bradyarrhythmia may require pacemaker implantation as definitive management. Conclusion: Congenital third-degree AV bock requires early diagnosis and timely treatment, because associated perinatal morbidity and mortality are high. Studies with better methodological quality are needed in order to endorse other promising therapeutic options and approaches.