title: Influence of acute variations in hematocrit on the QRS complex of the Frank electrocardiogram.
mesh_terms: D000293:Adolescent; D000328:Adult; D001803:Blood Transfusion; D001810:Blood Volume; D002648:Child; D002675:Child, Preschool; D004553:Electric Conductivity; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D006400:Hematocrit; D006801:Humans; D008297:Male; D011086:Polycythemia / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D013789:Thalassemia / Q000175:diagnosis* / Q000628:therapy; D014672:Vectorcardiography