Changes of the cardiac structure and function in Han people returning to lower altitude for at least 3 years after long-term exposure to high altitude

OBJECTIVE To study the changes of cardiac structure and function in Han people returning to the plain after long-term exposure to high altitude. METHODS Echocardiographic examinations were performed in 348 residents who once lived in high altitude and then returned to the plain for at least 3 years (altitude exposure group) and in 86 healthy people not exposed to high altitude (control group). The cardiac function and structure were measured and compared between two groups according to different genders. RESULTS Compared with the control group, the right atrium short diameter (RAD) was longer in altitude exposure group (male 30.81 ± 3.89 vs. 29.39 ± 3.93; female 29.05 ± 3.06 vs. 27.40 ± 2.97, P all﹤ 0.05). Left ventricular posterior wall thickness ( LPVW) in altitude exposure group was larger than in control group ( P ﹤ 0.05). The incidence of tricuspid regurgitation (TR) in altitude exposure group was significantly higher than that of the plain control (44.25% vs. 8.13%, P = 0.000). In altitude exposure group, the incidence of TR in females was higher than that in males (50.28% vs. 38.15%, P = 0.025). CONCLUSION Long-term exposure to high altitude is associated with the changes of the structure of right atrium and left ventricular, and the increased incidence of TR, which is higher in females than in males. And these changes mentioned above are hard to recover even after returning to the plain for several years.