Cueto García L, Martínez Natera O, Meaney E
Arch Inst Cardiol Mex. 1976 Sep-Oct;46(5):571-8.
The electrocardiograms of 150 newborns who were born in Mexico City (2,240 m. above sea level) were obtained in the first 24 hours of life and six weeks later. The electrocardiographic changes were similar to those observed at sea level; AQRS shifted to the left, the T waves became negative in the right precordial leads and the R/S relation increased in the left precordial leads. Mid-altitude does not affect the pulmonary vascular maturation of the normal newborn.
对150名在墨西哥城（海拔2240米）出生的新生儿，在其出生后的头24小时内及六周后进行了心电图检查。心电图变化与在海平面观察到的相似；额面QRS电轴左偏，右胸前导联T波变为负向，左胸前导联R/S比值增加。中等海拔不影响正常新生儿的肺血管成熟。
