Evaluation of cardiac index and right ventricular hypertrophy index in rats under a chronic hypoxic environment at high altitude

Yanqiu Sun; Jinfeng Ma; Tingjun Yan; Dengfeng Tian; Chenhong Zhang; Fengjuan Zhang; Yuchun Zhao; Shihan Fu; Chunlong Yan

doi:10.1016/j.heliyon.2024.e25229

Evaluation of cardiac index and right ventricular hypertrophy index in rats under a chronic hypoxic environment at high altitude

Heliyon. 2024 Jan 28;10(3):e25229. doi: 10.1016/j.heliyon.2024.e25229. eCollection 2024 Feb 15.

Authors

Yanqiu Sun^{1

2}, Jinfeng Ma³, Tingjun Yan⁴, Dengfeng Tian¹, Chenhong Zhang¹, Fengjuan Zhang^{1

5}, Yuchun Zhao^{1

5}, Shihan Fu^{1

5}, Chunlong Yan⁶

Affiliations

¹ Department of Radiology, Qinghai Provincial People's Hospital, Xining, China.
² Suzhou Medical College of Soochow University, Suzhou, China.
³ Department of Hematology, Jining No.1 People's Hospital, Jining, China.
⁴ Jining Medical College, Jining, China.
⁵ Graduate School of Qinghai University, Xining, China.
⁶ Department of Radiology, Jining No.1 People's Hospital, Jining, China.

Abstract

High-altitude areas are characterized by low pressure and hypoxia, which have a significant impact on various body systems. This study aimed to investigate the alterations in cardiac index and right ventricular hypertrophy index(RVHI) in rats at different altitudes.Twenty-one male Sprague-Dawley (SD) rats aged 4 weeks were randomly divided into three groups based on altitude. The rats were raised for 28 weeks and then transferred to Qinghai University Plateau Medicine Laboratory. Body weight was measured, heart organs were isolated and weighed, and cardiac index and right ventricular hypertrophy index were determined. Statistical analysis was performed on the data from the three groups. Compared with the plain group, the body weight of the middle-altitude group was significantly decreased (P < 0.05), and cardiac index, RVHI-1, RVHI-2 increased significantly ((P < 0.05). The body weight, whole heart mass, right ventricular mass were significantly decreased in high-altitude group (P < 0.05), RVHI-1 and RVHI-2 were significantly increased (P < 0.05). Compared with the middle-altitude group, the body weight, whole heart mass and right ventricular mass of the high-altitude group were significantly decreased (P < 0.05), and RVHI-1 and RVHI-2 were significantly increased (P < 0.05). Increasing altitude led to a decrease in body weight, whole heart mass, and right ventricular mass in rats, indicating structural changes in the right heart. Additionally, the proportion of right heart to body weight and whole heart increased with altitude.

Keywords: Body weight; Cardiac index; Different altitudes; Rats; Right ventricular hypertrophy index.