[Risk factors of pulmonary arterial hypertension in patients with atrial septal defect at high altitude area].

OBJECTIVE: To analyze risk factors of pulmonary arterial hypertension (PAH) in patients with atrial septal defect (ASD) patients living at above 2000 m high altitude area. METHODS: We retrospectively analyzed the incidence of PAH in 526 ASD patients out of 1178 congenital heart disease patients who were hospitalized in Qinghai cardiovascular hospital between January 2007 to December 2009 and explored the risk factors including gander, age, altitude, defect size and nationalities for developing PAH in ASD patients using binary logistic regression. RESULTS: PAH prevalence was 68.4% (360/526) in ASD patients. The risk factors of developing PAH in these ASD patients were defect size (OR: 1.200, 95%CI: 1.156 - 1.246, P = 0.000), age (OR: 1.027, 95%CI: 1.003 - 1.052, P = 0.025) and altitude (OR: 1.389, 95%CI: 1.001 - 1.637, P = 0.043) while gender and nationality were not risk factors for PAH. The incidence of developing PAH increased with aging (P = 0.000). The standardized ratio of PAH at ≥ 3500 m was 74.8% which was significantly higher than that at 2000 - 2499 m altitude (66.2%, P = 0.005) and at 2500 - 3499 m altitude (66.9%, P = 0.005). CONCLUSIONS: The risk for developing PAH is high in patients living at high altitude area. The risk factors of developing PAH in ASD patients living at high altitude are defect size, age and altitude.

[Susceptibility of patients with congenital heart disease to pulmonary hypertension at a high altitude].

OBJECTIVE: To explore the incidence of congenital heart disease (CHD) complicated with pulmonary arterial hypertension (PAH) at an altitude of over 2000 meters above sea level. METHODS: We retrospectively analyzed the profiles of 688 PAH patients selected from 1178 CHD patients at our hospital during January 2007 to December 2009. The risk factors of CHD-PAH were analyzed by age, altitude, etiologies and nationalities. RESULTS: Among 1178 CHD patients, 688 (58.4%) suffered PAH. And 239 PAH cases (54.8%) were found in 436 male patients and 449 PAH cases (60.5%) in 742 female patients (χ(2) = 3.667, P = 0.058). The difference was not significant. The incidences of PAH in CHD patients varied at different altitudes (χ(2) = 10.507, P = 0.005). And 55.2%, 57.2% and 68.7% were found in < 2500 m, 2500 - 3500 m and > 3500 m groups respectively. And the > 3500 m group was statistically higher than those of the < 2500 m and 2500 - 3500 m groups (χ(2) = 9.924, P = 0.005) (χ(2) = 8.007, P = 0.005). The mean pulmonary arterial systolic pressure (PASP) of < 2500 m group was (58 ± 18) mm Hg, 2500 - 3500 m was (63 ± 17) mm Hg and > 3500 m was (64 ± 19) mm Hg. There were significant differences among them. In age composition of CHD-PAH, the highest ratio appeared before the age of 18 years old for PDA (patent ductus arteriosus)-PAH and VSD (ventricular septal defect)-PAH while that of ASD-PAH at the ages of 30 - 39 years old. There were not statistical differences among all nationalities (χ(2) = 5.404, P = 0.248). CONCLUSION: The incidence of CHD-PAH at a high altitude is significantly higher than those at a low altitude. Hypoxia may promote the occurrence and development of PAH in CHD patients.

[A cross-sectional study of congenital heart disease among children aged from 4 to 18 years at different altitudes in Qinghai province, China].

OBJECTIVE: The epidemiological characteristics of congenital heart disease (CHD) in children aged from 4 to 18 years were investigated in Qinghai province. METHODS: Altogether 288 066 children inhabiting at 6 prefectures and 3 counties were examined by the following three steps: pre-screening, re-examination and diagnosis with color Doppler. And the entity distribution was analyzed while the differences were compared by age, gender, altitudes and nationalities respectively. RESULTS: Altogether 1633 cases of CHD were discovered. The total prevalence of CHD was 5.71 per thousand. The prevalence of CHD was found to increase with the increase of altitude by 4.89 per thousand at the altitude of 2535 m, 5.71 per thousand at 3600 m, and 8.74 per thousand at 4200 m respectively. There were significant differences among different altitude (chi(2) = 54.696, P < 0.001). chi(2) trend analysis showed the increase with chi(2) = 41.826(P < 0.001). The total incidence of CHD in females was 6.95 per thousand, which was significantly higher than that in males with 4.54 per thousand (chi(2) = 73.79, P < 0.001). There were significant differences between males and females at the altitude of 3000 m (chi(2) = 84.733, P < 0.001) and 4000 m (chi(2) = 16.313, P < 0.001) except at the altitude of 2000 m (chi(2) = 0.807, P > 0.05). The prevalence of CHD in different age groups was statistically significant at the every altitude of 2000 m (chi(2) = 18.138, P < 0.001), 3000 m (chi(2) = 18.544, P < 0.001) and 4000 m (chi(2) = 27.535 P < 0.001). The prevalence of CHD was increasing with the increase of age groups at the altitude of 3000 m (chi(2) = 19.230, P < 0.001) and 4000 m (chi(2) = 26.894, P < 0.001) except at the altitude of 2000 m. Within the prevalence of CHD of different nationalities, there was a significant difference with chi(2) = 24.456 (P < 0.001). Within the constituent rate of CHD, the prevalence of atrial septal defect (ASD) was as high as 37.42%, followed by the prevalence of patent ductus arteriosus (PDA) as 28.47% and ventricular septal defect (VSD) as 26.01%. Regarding the four categories of CHD, the constituent rate varied at different altitudes. For example, the prevalence rate of ASD constituted 37% at the altitude of 2000 m and 3000 m, and that of PDA accounted for 46.36% at the altitude of 4200 m. CONCLUSION: The epidemiological characteristics of CHD in Qinghai children were possibly associated with altitude levels.

[Study on the epidemiology of congenital heart disease in Tibetan ethnic children aged from 4 to 18 living at different altitudes in Qinghai province].

OBJECTIVE: The epidemiological characteristics of congenital heart disease (CHD) among Tibetan children whose age ranged from 4 to 18 at different altitude were investigated in Qinghai province. METHODS: 32 578 Tibetan children living at 2535 m, 3600 m and 4200 m were surveyed with the following 3 steps: prescreened, counterchecked and diagnosed with color Doppler. The entity distribution was then analysed and the age and gender were compared respectively. RESULTS: 235 CHD cases were identified. The total morbidity was 7.21 per thousand. CHD morbidity was rising with the increase of altitude with 5.45 per thousand at 2535 m, 6.80 per thousand at 3600 m and 9.79 per thousand at 4200 m respectively. There were significant static differences between 4200 m and the others with chi2 = 7.002 (P < 0.01) to 2535 m and chi2 = 5.540 (P < 0.05) to 3600 m. However, there was no statistical difference between 2535 m altitude and 3600 m altitude. The morbidity in different age had no statistical difference at 2535 m altitude but statistically increased with the increase of age at 3600 m and 4200 m. The total ratio of 16-18 age was significantly higher than other age periods with chi2 = 10.79 (P < 0.005) to 4-7 age period and with chi2 = 5.60 (P < 0.05) to 8-12 age period. The atrial septal defect (ASD) morbidity rates in three places was 39.1% followed by ventricular septal defect (VSD) with 32.8% and patent ductus arteriosus (PDA) with 24.7%. However, the constitute of CHD was different in different altitudes that VSD with 43.5% at 2535 m, ASD with 42.8% at 3600 m and PDA with 50.8% at 4200 m which was the highest morbidity. CONCLUSION: Morbidity, constitutes and difference in gender and age were related to altitude.