title: Left ventricular function during acute high-altitude exposure in a large group of healthy young Chinese men.
abstract: OBJECTIVE
  The purpose of this study was to observe left ventricular function during acute high-altitude exposure in a large group of healthy young males.
  
  
  METHODS
  A prospective trial was conducted in Szechwan and Tibet from June to August, 2012. By Doppler echocardiography, left ventricular function was examined in 139 healthy young Chinese men at sea level; within 24 hours after arrival in Lhasa, Tibet, at 3700 m; and on day 7 following an ascent to Yangbajing at 4400 m after 7 days of acclimatization at 3700 m. The resting oxygen saturation (SaO2), heart rate (HR) and blood pressure (BP) were also measured at the above mentioned three time points.
  
  
  RESULTS
  Within 24 hours of arrival at 3700 m, the HR, ejection fraction (EF), fractional shortening (FS), stroke volume (SV), cardiac output (CO), and left ventricular (LV) Tei index were significantly increased, but the LV end-systolic dimension (ESD), end-systolic volume (ESV), SaO2, E/A ratio, and ejection time (ET) were significantly decreased compared to the baseline levels in all subjects. On day 7 at 4400 m, the SV and CO were significantly decreased; the EF and FS Tei were not decreased compared with the values at 3700 m; the HR was further elevated; and the SaO2, ESV, ESD, and ET were further reduced. Additionally, the E/A ratio was significantly increased on day 7 but was still lower than it was at low altitude.
  
  
  CONCLUSIONS
  Upon acute high-altitude exposure, left ventricular systolic function was elevated with increased stroke volume, but diastolic function was decreased in healthy young males. With higher altitude exposure and prolonged acclimatization, the left ventricular systolic function was preserved with reduced stroke volume and improved diastolic function.
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Mingyue
authors: M
authors: Rao
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Jiabei
authors: J
authors: Li
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Jun
authors: J
authors: Qin
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China.
authors: Jihang
authors: J
authors: Zhang
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China.
authors: Xubin
authors: X
authors: Gao
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Shiyong
authors: S
authors: Yu
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China.
authors: Jie
authors: J
authors: Yu
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Guozhu
authors: G
authors: Chen
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Baida
authors: B
authors: Xu
authors: Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Huijie
authors: H
authors: Li
authors: Department of Medical Ultrasonics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Rongsheng
authors: R
authors: Rao
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Lan
authors: L
authors: Huang
authors: Institute of Cardiovascular Diseases of PLA, Third Military Medical University, Chongqing 400037, China; Department of Cardiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors: Jun
authors: J
authors: Jin
mesh_terms: D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000175:diagnosis / Q000503:physiopathology; D002302:Cardiac Output; D018619:Echocardiography, Doppler, Pulsed; D064368:Healthy Volunteers; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D009929:Organ Size; D016276:Ventricular Function; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
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