Study of Cardiovascular Manifestations in Patients with Thyroid dysfunction at Tertiary Care Center

Abstract

Introduction: Thyroid hormones have effects on virtually every organ system. The heart is the major target organ for thyroid action. It was thought that thyroid disorder is a circulatory disorder and manifestations of thyroid disorders are due to changes in cardiac work. Over the period it has become clear that the explanation for the altered circulatory hemo-dynamics of thyroid disease is because of involvement of cardiovascular system. Aims and Objectives: To find out the incidence of overt and subclinical cardiac manifestations in patients with thyroid dysfunction and to compare the prevalence of overt and subclinical cardiac manifestations in two subsets of patients belonging to hyperthyroid and hypothyroid groups respectively. Materials and Methods: It was an observational study carried out at the Department of Medicine for the period of August 2017 to December 2019. In total, 230 newly diagnosed patients with thyroid dysfunction were included in the study. Focused clinical and detailed cardiovascular system examination, necessary biochemical investigations were done. All patients underwent detailed 12 lead electrocardiogram and 2D Echo-cardiography procedure. Incidence of overt and subclinical cardiac manifestations in Hyperthyroid and Hypothyroid cases was calculated; and the Prevalence of overt and subclinical manifestations in the two subsets of patients belonging to Hyperthyroid and Hypothyroid groups respectively was compared and data was analyesd. Results: Total hypothyroid patients were 115 and that of hyperthyroid were 115. Incidence of thyroid is much more common in females as compared to males (81% in hyperthyroidism and 92% in hypothyroidism). In hyperthyroid group, 92% patients showed cardiac involvement either in the form of ECG, CXR, 2D ECHO abnormalities and in hypothyroid patients it was 93%. Statistically significant patients presented with symptoms of congestive cardiac failure in hyperthyroid group (73%) but not in hypothyroid group. In the both groups, fatigue was the most commonest presenting symptom related to cardiovascular system. In hypothyroid group, most common cardiac sign was Pulse, Pressure<40 mm of Hg (73%) whereas in hyperthyroidism it was sinus tachycardia (73%). 73% hyperthyroid patients showed sinus tachycardia as the most common ECG finding where again 73% hypothyroid patients showed ST-T changes as a most common ECG finding. Nearly 70% hyperthyroid patients had ejection fraction more than 60% on Echocardiogrphy the procedure and almost all patients of hypothyroidism had ejection fraction less than 60%. Conclusion: Thyroid dysfunction was found to be more common in the females with 41-50 years of age group in hypothyroidism group and 21-30 years in the hyperthyroidism group. Cardiovascular manifestations were the major presenting factors in both the groups pointing towards the adverse effects of thyroid dysfunction, Dyspnea and fatigue were the major cardiac symptoms in the hypothyroidism group. While chest pain and fatigue were the major cardiac symptoms in the hyperthyroidism group. The ECG and 2D ECHO findings in the current study also suggested that in both the groups of thyroid dysfunction, cardiac manifestations are likely to have higher incidence.