title: The relation of frontal QRS axis to age and body build.
mesh_terms: D000328:Adult; D000367:Age Factors; D001827:Body Height; D001835:Body Weight; D004562:Electrocardiography / Q000592:standards; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013008:Somatotypes; D013909:Thorax / Q000033:anatomy & histology