Electrocardiographic Evidence for Right Heart Strain in Asymptomatic Children Living in Tibet - A Comparative Study between Han Chinese and Ethnic Tibetans

Abstract

Objective.-To compare ethnic Tibetan children with Han Chinese migrants for signs of right ventricular strain using electrocardiography (ECG) that would suggest chronic hypoxia at altitudes of 3500 to 4500 m above sea level. Methods.-One hundred thirty-five asymptomatic school children aged 7 to 12 years were assessed for height, weight, and blood pressure and underwent a single ECG at 2 centers at 3500 and 4500 m. A questionnaire was given to parents to provide demographic data with relevant medical history. Results.-There was a high prevalence of right ventricular strain on ECG for both Tibetan and Han children (33%) with no significant difference between the 2 ethnic groups or sexes. Conclusions.-Other studies showing higher observed rates of symptomatic chronic altitude sickness in Han Chinese children suggest that other extracardiologic factors play a role in the pathogenesis of the disease.