Chen Xu, Liu Bohan, Deng Yujiao, Yang Feifei, Wang Wenjun, Lin Xixiang, Yu Liheng, Pu Haitao, Zhang Peifang, Li Zongren, Zhong Qin, Jia Qian, Li Yao, Wang Xiao, Chen Wei, Burkhoff Daniel, He Kunlun
Beijing Key Laboratory for Precision Medicine of Chronic Heart Failure, Key Laboratory of Ministry of Industry and Information Technology of Biomedical Engineering and Translational Medicine, Translational Medicine Research Center, Medical Artificial Intelligence Research Center, Chinese PLA General Hospital, Beijing, China.
BioMind Technology, Zhongguancun Medical Engineering Center, Beijing, China.
Front Cardiovasc Med. 2022 May 23;9:856749. doi: 10.3389/fcvm.2022.856749. eCollection 2022.
Exposure to high altitudes represents physiological stress that leads to significant changes in cardiovascular properties. However, long-term cardiovascular adaptions to high altitude migration of lowlanders have not been described. Accordingly, we measured changes in cardiovascular properties following prolonged hypoxic exposure in acclimatized Han migrants and Tibetans.
Echocardiographic features of recently adapted Han migrant (3-12 months, = 64) and highly adapted Han migrant (5-10 years, = 71) residence in Tibet (4,300 m) using speckle tracking echocardiography were compared to those of age-matched native Tibetans ( = 75) and Han lowlanders living at 1,400 m ( = 60).
Short-term acclimatized migrants showed increased estimated pulmonary artery systolic pressure (PASP) (32.6 ± 5.1 mmHg vs. 21.1 ± 4.2 mmHg, < 0.05), enlarged right ventricles (RVs), and decreased fractional area change (FAC) with decreased RV longitudinal strain (-20 ± 2.8% vs. -25.5 ± 3.9%, < 0.05). While left ventricular ejection fraction (LVEF) was preserved, LV diameter (41.7 ± 3.1 mm vs. 49.7 ± 4.8 mm, < 0.05) and LV longitudinal strain (-18.8 ± 3.2% vs. -22.9 ± 3.3%, < 0.05) decreased. Compared with recent migrants, longer-term migrants had recovered RV structure and functions with slightly improved RV and LV longitudinal strain, though still lower than lowlander controls; LV size remained small with increased mass index (68.3 ± 12.7 vs. 59.3 ± 9.6, < 0.05). In contrast, native Tibetans had slightly increased PASP (26.1 ± 3.4 mmHg vs. 21.1 ± 4.2 mmHg, < 0.05) with minimally altered cardiac deformation compared to lowlanders.
Right ventricular systolic function is impaired in recent (<1 year) migrants to high altitudes but improved during the long-term dwelling. LV remodeling persists in long-term migrants (>5 years) but without impairment of LV systolic or diastolic function. In contrast, cardiac size, structure, and function of native Tibetans are more similar to those of lowland dwelling Hans.
暴露于高海拔地区会带来生理应激，导致心血管特性发生显著变化。然而，低landers长期向高海拔地区迁移后的心血管适应性变化尚未得到描述。因此，我们测量了适应环境的汉族移民和藏族人在长期低氧暴露后的心血管特性变化。
使用斑点追踪超声心动图比较了近期适应的汉族移民（3 - 12个月，n = 64）和长期适应的汉族移民（5 - 10年，n = 71）在西藏（4300米）居住时的超声心动图特征，与年龄匹配的本地藏族人（n = 75）和生活在1400米的汉族低landers（n = 60）进行比较。
短期适应的移民显示估计肺动脉收缩压（PASP）升高（32.6±5.1 mmHg对21.1±4.2 mmHg，P < 0.05），右心室（RV）增大，面积变化分数（FAC）降低，RV纵向应变降低（-20±2.8%对-25.5±3.9%，P < 0.05）。虽然左心室射血分数（LVEF）得以保留，但左心室直径（41.7±3.1 mm对49.7±4.8 mm，P < 0.05）和左心室纵向应变（-18.8±3.2%对-22.9±3.3%，P < 0.05）降低。与近期移民相比，长期移民的RV结构和功能有所恢复，RV和LV纵向应变略有改善，尽管仍低于低landers对照组；左心室大小仍然较小，质量指数增加（68.3±12.7对59.3±9.6，P < 0.05）。相比之下，与低landers相比，本地藏族人的PASP略有升高（26.1±3.4 mmHg对21.1±4.2 mmHg，P < 0.05），心脏变形变化最小。
近期（<1年）迁移到高海拔地区的移民右心室收缩功能受损，但在长期居住期间有所改善。长期移民（>5年）存在左心室重构，但左心室收缩或舒张功能未受损。相比之下，本地藏族人的心脏大小、结构和功能与居住在低海拔地区的汉族人更为相似。
