Abstract 10096: Anatomical and Hemodynamic Evaluations of the Heart And Pulmonary Arterial Pressure in Healthy Han and Tibetan Children Residing at High Altitude in China
Objectives: Altitude hypoxia may induce pulmonary artertial hypertension and cardiac anatomic and functional alterations, which have not been assessed in healthy children. We aimed to compare the cardiopulmonary measures in healthy Hans and Tibetans aged at 0-14 years residing at low, mid-high and very high altitudes.
Methods: Echocardiographic assessments were prospectively collected in 1061 children (median 6.5y) at 16m (n=218), 2260m (n=567) and 3700m (n=276). Cardiac anatomic measures included the dimensions of the four chambers (RA, RV, LA, LV) , main pulmonary artery (MPA) and aortic root, thickness of ventricular walls and interventricular septum (IVS). Systolic function included ejection fraction and fractional shortening of LV and RV with cardiac output. Diastolic function included of E and A waves of tricuspid and mitral valves, isovolumic relaxation time of LV and RV. Mean pulmonary arterial pressure (mPAP) was estimated with pulmonary preejection period, accelerating and ejection time. All children were divided into 7 age groups (0-28d-6m-1y-3-6y-10y-14y). Age-adjusted comparisons of these measures were made among 3 altitude groups and between Hans (n=165) and Tibetans (n=111) at 3700m.
Results: No significant difference was found between 16m and 2260m groups. Significantly in those at 3700m, RA, RV and MPA were larger, RV anterior wall and IVS thicker, and LV smaller after 6m (p<0.05); Diastolic function was poorer with lower E wave, higher A and longer isovolumic relaxation time after 6m for RV and 6y for LV respectively. mPAP was higher, plateauing after 3y (p< 0.01). Ventricular systolic function was not different among 3 groups (p>0.05). There was no difference in any of the measure between the Hans and Tibetans at 3700m (p>0.05).
Conclusions: Children residing at very high altitude have significantly higher pulmonary arterial pressure, larger RV and smaler LV with decreased diastolic function, occurring in different years of growth. Systolic function is preserved. The adaptaions are not significantly different between Hans and Tibetans. These values provide reference for future studies in children with congenital and acquired cardiopulmonary diseases.
- © 2013 by American Heart Association, Inc.