Key result
Short-term high altitude exposure linked to ~25% higher Tei index, indicating delayed global cardiac recovery.
Why the study?
High altitude de-adaptation mechanisms affecting cardiac function after return to low altitude remain unclear.
Does short-term exposure to high altitude alter cardiac function and pulmonary arterial pressure upon return to the plains in healthy young males?
Cohort (n=194)
Random sampling from a unit
No
Does short-term exposure to high altitude alter cardiac function and pulmonary arterial pressure upon return to the plains in healthy young males?
Absolute Event Rate: 0.4% vs 0.32%
p-value: p=<0.01
Global cardiac function, as measured by the Tei index, remains impaired for at least 15 days after returning to low altitude following short-term high altitude exposure, indicating a prolonged de-adaptation process.
Delayed cardiac recovery may persist after high-altitude return; hypothesis-generating and requires validation before clinical consideration.
High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m) and returned to the plains (1500 m) after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP), left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), cardiac function index (Tei index) were tested. Levels of serum creatine kinase isoform MB (CK-MB), lactate dehydrogenase isoenzyme-1 (LDH-1), endothelin-1 (ET-1), nitrogen oxide (NO), serum hypoxia-inducible factor-1α (HIF-1α), 8-iso-prostaglandin F(2α) (8-iso PGF(2α)), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th) day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01). We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α) levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.
No takes yet. Share an insight, caveat, or question.
Zhou et al. (2012) conducted a cohort in High altitude exposure (n=194). Short-term exposure to high altitude (3700 m) and return to plains vs. Remaining at low altitude (1500 m) was evaluated on Cardiac function (Tei index) on the 15th day after return to low altitude (p=<0.01). Short-term exposure to high altitude followed by return to the plains resulted in a persistently elevated Tei index compared to controls on the 15th day, indicating delayed recovery of global cardiac function.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: