Cardiovascular Changes in Hypothyroidism, a Tertiary Centre Study

ABSTRACT

Background:Among the commonly existing endocrine disorders found in India, Thyroid disease contributes fairly to the clinical scenario affecting around 9-15 % of the female population as well as the male population to a milder degree. Among the principal targets of the thyroid hormones is the cardiovascular system. The effects noted on the CVS are changes in the cardiac contractility, myocardial oxygen consumption, alterations in the systemic vascular resistance (SVR), decreased cardiac contractility leading to decreased cardiac output, increased rate of atherosclerosis and hence greater potential of CAD. Hypothyroidism also causes QT interval prolongation. Only few studies have been done in our country to assess these cardiovascular parameters in hypothyroid patients. Principally the thyroid hormone-T3, affects the heart with variations in cardiac gene expression principally mediated by T3. On 2D-ECHO mild Left Ventricular Diastolic Dysfunction (LVDD), mild concentric Left Ventricular Hypertrophy (LVH) with or without Left Ventricular Diastolic Dysfunction, mild mitral insufficiency or minimal pericardial effusion can be found. Since there does exist some evidence of a causal relationship, it is advisable to perform a basic cardiac work-up which should also include an echocardiogram to assess systolic and diastolic dysfunction as part of initial evaluation of the hypothyroid patients. Also to make note is the fact that persistent subclinical thyroid dysfunction may notably increase the cardiovascular disease risk ratio.