title: Letter to the editor in response to the case report entitled "the two-headed swan".
authors.forename: James
authors.initials: J
authors.lastname: Wallis
mesh_terms: D016477:Artifacts; D002408:Catheters, Indwelling; D016638:Critical Illness; D006801:Humans; D009038:Motion; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic; D013617:Tachycardia, Supraventricular / Q000000981:diagnostic imaging / Q000628:therapy; D013997:Time Factors