How to Cite: El Sherif, A. H., Elhusseiny, R. M., Zaghla, H. E., Ahmed, A. F., & Youssef , M. S. I. (2022). Thyroid dysfunction and its relation to myocardial performance among patients with acute myocardial infarction. International Journal of Health Sciences, 6(S1), 2323–2334. https://doi.org/10.53730/ijhs.v6nS1.5169 International Journal of Health Sciences ISSN 2550-6978 E-ISSN 2550-696X © 2022. Corresponding author: Youssef, M.S.I.; Email: dr.moh.salah83@gmail.com Manuscript submitted: 18 Nov 2021, Manuscript revised: 09 Feb 2022, Accepted for publication: 27 March 2022 2323 Thyroid Dysfunction and its Relation to Myocardial Performance among Patients with Acute Myocardial Infarction Ahmed Hussein El Sherif Professor of critical care medicine, Faculty of Medicine, Cairo University, Cairo, Egypt Rania Mostafa Elhusseiny Professor of critical care medicine, Faculty of Medicine, Cairo University, Cairo, Egypt Hanan Elsayed Zaghla Professor of critical care medicine, Faculty of Medicine, Cairo University, Cairo, Egypt Abdelraof Fahmy Ahmed Lecturer of critical care medicine, Faculty of Medicine, Cairo University, Cairo, Egypt Mohammed Salah Ismail Youssef Critical Care Specialist, Faculty of Medicine, Cairo University, Cairo, Egypt Abstract---Background: The cardiovascular system is one of the most important targets on which thyroid hormones act, thyroid hormone has a major role in the cardiovascu¬lar system function and cardiac hemodynamics. Objectives: The primary aim of our study was to evaluate the prevalence of thyroid dysfunction in patients with acute myocardial infarction and to study the impact of these dysfunctions on in-hospital morbidity and mortality among those subjects. Patients and Methods: This study was conducted on one hundred critically ill patients admitted to the critical care department with the diagnosis of acute myocardial infarction in the period from April 2017 to January 2019. Results: According to thyroid profile, 78 patients (78%) had euthyroid status and the remaining 22 patients (22%) had thyroid dysfunctions which include: 12 patients (54.54%) were euthyroid sick syndrome, 7 patients (13.81%) had subclinical hypothyroidism, 3 patients (13.63%) had subclinical hyperthyroidism. Conclusion: Thyroid dysfunction in association with acute myocardial