333 April 2025. Volume 19. Number 2 Hamed Zarei 1* , Hamid Yaeghoobzadeh 2 , Leila Mohammadyar 2 1. Department of Biology, Faculty of Basic Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran. 2. Department of Basic Sciences, Faculty of Veterinary Medicine, Garmsar Branch, Islamic Azad University, Garmsar, Iran. * Corresponding Author: Hamed Zarei, Associate Professor. Address: Department of Biology, Faculty of Basic Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran. Phone: +98 (21) 36726951 E-mail: h.zarei@iautmu.ac.ir Original Article Effects of Vitamin E on Electrocardiographic Parameters of Broiler Chickens With Pulmonary Hypertension Background: Pulmonary hypertension in broiler chickens is a multifactorial syndrome leading to significant mortality, primarily due to hypoxemia and cardiac overload. Objectives: This study aimed to assess the impact of vitamin E supplementation on electrocardiographic parameters in broiler chickens subjected to triiodothyronine (T3)- induced pulmonary hypertension. Methods: A total of 180 chicks were randomly assigned to four groups: One control and three treatment groups. The chicks in the treatment groups received vitamin E (α-tocopherol) at doses of 100, 200, and 400 IU from one day to 49 days of age. To induce pulmonary hypertension, all chicks were administered 1.5 mg/kg of T3 from the seventh day to the end of the experiment through their diet. Electrocardiograms were recorded at 14 and 49 days of age, and right ventricular hypertrophy (RVH) was assessed post-euthanasia. Results: Significant decreases in the right ventricle/ total ventricle weight (RV/TV) ratio were observed in the treated groups on day 49 (P<0.05). Electrocardiographic analysis revealed reductions in S, T, and R wave amplitudes specifically on day 49 for all vitamin E doses (P<0.05). The QRS interval significantly increased at all doses on day 49, while the RR interval increased at certain doses on days 14 and 49 compared to the control group (P<0.05). Conclusion: Vitamin E supplementation effectively modulates the induction of pulmonary hypertension and associated ventricular hypertrophy in broiler chickens. Keywords: Broiler chickens, Electrocardiographic parameters, Pulmonary hypertension, Triiodothyronine (T3), Vitamin E A B S T R A C T How to Cite This Article Zarei, H., Yaeghoobzadeh, H., & Mohammadyar, L. (2025). Effects of Vitamin E on Electro- cardiographic Parameters of Broiler Chickens With Pulmonary Hypertension. Iranian Journal of Veterinary Medicine, 19(2), 333-340. http://dx.doi.org/10.32598/ijvm.19.2.1005708 http://dx.doi.org/10.32598/ijvm.19.2.1005708 Use your device to scan and read the article online Article info: Received: 23 Dec 2024 Accepted: 10 Mar 2025 Publish: 01 Apr 2025 Copyright © 2025 The Author(s); This is an open access article distributed under the terms of the Creative Commons Attribution License (CC-By-NC: https://creativecommons.org/licenses/by-nc/4.0/legalcode.en), which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.