title: Letter to the editor: response to Ballestero et al.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Heerdt
mesh_terms: D002302:Cardiac Output / Q000502:physiology*; D002307:Cardiography, Impedance / Q000295:instrumentation*; D002318:Cardiovascular Diseases / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male