It was recognized for many years that the incidence of myocardial infarction was obviously low in highland habitant, suggesting that long-term adaptation to altitude hypoxia has cardiac protection. 1 Cumulating evidence demonstrates that exposure to chronic intermittent hypobaric hypoxia (CIHH) simulating altitude hypoxia increases the tolerance of myocardium to ischemia and hypoxia, and exerts a protective effect on the heart. 2,3 Our previous studies showed that CIHH promotes the recovery of damaged cardiac function, reduces the infarct size, and prevents arrhythmia during ischaemia/reperfusion. 2,4-6 In spite of multiple mechanisms and signalling pathways for the cardiac protective role of CIHH have been