Cross-sectional study of electrocardiographic pattern in healthy children resident at high altitude.

Electrocardiographic studies have reported persistent right ventricle predominance in high altitude children as an adaptive response. No information was provided on ethnicity and environmental factors in those studies. We assessed the electrocardiographic characteristics in healthy high altitude children with mixed ancestry and relatively high mobility to lower altitudes. A cross-sectional study of 321 children aged 2 months through 19 years old and living at high altitude (Tintaya, Peru, 4,100 m) was conducted. Standard 12-lead electrocardiography was performed. Information was obtained on ethnicity, medical history, place and altitude of pregnancy and birth, mobility of children and their parents and grandparents to lower altitudes, and housing conditions. A medical examination, echocardiography, hemoglobin, oxygen saturation, and anthropometric measurements were performed. Means between sexes were compared through Mann-Whitney test for independent samples not normally distributed. Potentially influential variables on electrocardiographic values were controlled through a general linear model. Electrocardiographic parameters including QRS axis, RV1, RSV1, RV1SV5, RSV5, RSV6, and SV1RV5 did not show a right predominance pattern at any age. Values were within sea level norms. None of the genetic or environmental factors controlled showed a consistent influence on the electrocardiographic variables. Our study showed an electrocardiographic pattern similar to that of sea level in high altitude children with some degree of high-altitude ancestry, comparatively well-nourished and with relatively high mobility to low altitudes.