Congenital Heart Disease and Thyroid Dysfunction: Combination, Association, and Implication

Background: Patients with congenital heart disease have higher prevalence of thyroid dysfunction due to embryonic and genetic coexistence. Marked changes in cardiac function occur secondary to alternations in thyroid hormone levels. Cardiac catheterizations or cardiac surgeries with cardiopulmonary bypass can cause abnormalities in the circulating hormones, in the absence of primary thyroid disease. Therefore, monitoring of thyroid function should be routinely performed in children with congenital heart disease. Thyroid hormone supplementation has been postulated as a possible therapeutic option; however, the therapeutic decisions should be made based on individual circumstances, symptoms, and the severity of the thyroid dysfunction. Objectives: To describe the correlation between congenital heart disease in children and thyroid dysfunction and the debate on monitoring, intervention, and treatment. Methods: PubMed, Clinical Key, and the Cochrane Library were searched using keywords relevant to congenital heart disease/surgery, cardiopulmonary bypass, thyroid hormones, sick euthyroid syndrome, and cardiac catheterization. Studies were limited to the English language and to children 0 to 18 years old. Studies in adults with important findings were reviewed as well. All clinical studies believed to have relevance were considered. All relevant studies were reviewed, and the most pertinent data were incorporated in this review. Conclusion: There is lack of significant evidence concerning treatment for thyroid dysfunction in children with a congenital cardiac diagnosis. Adequately powered studies are needed before a uniform recommendation about treatment can be made.