INFLUENCE OF THYROID HORMONES ON CARDIAC FUNCTION AND STRUCTURE IN PATIENTS WITH CONGENITAL HYPOTHYROIDISM

Abstract

Introduction: Congenital hypothyroidism is a condition that results from a deficiency in thyroid function since birth, leading to a deficit in the production of thyroid hormones, such as T3 and T4. These hormones play a crucial role in the normal development and functioning of several organ systems, including the cardiovascular system. The influence of thyroid hormones on cardiac function and structure is complex, involving changes in heart rate, contractility, and myocardial structure. Objective: To examine and synthesize the evidence on the influence of thyroid hormones on cardiac function and structure in patients with congenital hypothyroidism, focusing on how hormonal deficiency impacts the cardiovascular system and which interventions can mitigate these effects. Methodology: The systematic review was performed following the PRISMA checklist, searching for articles published in the last 10 years in the PubMed, Scielo, and Web of Science databases. The descriptors "congenital hypothyroidism", "thyroid hormones", "cardiac function", "cardiac structure" and "pediatrics" were used to identify relevant studies. Studies that addressed the relationship between thyroid hormones and cardiac function in patients with congenital hypothyroidism, clinical trials and systematic reviews were included. The inclusion criteria were: studies that focused on patients with congenital hypothyroidism, research that analyzed cardiac function and structure and articles published in the last 10 years. Studies that did not directly address the relationship between hypothyroidism and cardiac function, articles outside the pediatric scope and research of low methodological quality were excluded. Results: The results indicated that congenital hypothyroidism causes significant changes in cardiac function, including bradycardia, decreased myocardial contractility and changes in heart rate. In terms of cardiac structure, ventricular hypertrophy and changes in the dimensions of the cardiac chambers were observed. Conclusion: Congenital hypothyroidism has a notable impact on cardiac function and structure, with evidence showing that thyroid hormone deficiency can lead to bradycardia, ventricular hypertrophy, and other structural changes. Hormone replacement therapy has been shown to be effective in mitigating these effects, highlighting the importance of early diagnosis and appropriate treatment to improve long-term cardiovascular health.