Dilated Cardiomyopathy Essay

Thyroid dysfunction in dilated cardiomyopathy: A systematic review

Dilated cardiomyopathy (DCM) is a major health problem. The estimated prevalence of dilated cardiomyopathy is 1:2500. [1] DCM is one of the most common types of cardiomyopathy. The disease typically occurs between the age of 20-60. [2] DCM is a progressive disease of the heart muscle. The disease is characterized by weakening of the ventricular myocardial muscle, resulting from elongation of myocytes accompanied by a vacuolar sarcoplasm and reduced myofibril density. [3] Weakening of the heart muscle results in a decreased stroke volume, leading to compensatory changes by a process called remodeling. The remodeling is characterized by elongation of myocytes by addition of sarcomeres, resulting in dilation -enlargement - of the heart while the wall thickness does not increase proportionally. This process of remodeling can spread to the other ventricle and to the atria. [4] The long-term effects of the remodeling are a further weakening of the heart muscle and it can eventually lead to heart failure. There are many postulated causes of DCM, including pregnancy, diabetes, alcohol, hypothyroidism or hyperthyroidism. [5] In 50%, the cause is not known (idiopathic DMC). [6] For this systematic review, we focus on the thyroid levels in patients with DCM. Thyroid hormone has major effects on the heart. For example in physiologic processes like metabolism, growth and development. Even small changes in thyroid hormone level can affect the heart and cardiovascular system. [7]

The investigations are important for the diagnosis and treatment of DCM. This review provides an overview of the indications that altered TH levels and thyroid dysfunction play a role in the onset and/or progression of dilated cardiomyopathy, and the mechanisms