title: Quadricuspid aortic valve not discovered by transthoracic echocardiography.
abstract: BACKGROUND
  Quadricuspid aortic valve is a rare congenital heart defect. Several different anatomical variations of a quadricuspid aortic valve has been described and aortic regurgitation is the predominant valvular dysfunction associated with quadricuspid aortic valve.
  
  
  METHODS
  A 68-year-old woman presented with almost a years history of increasing dyspnoea on exertion. The patient have had two previous transthoracic echocardiographic exams in the last six years and they had only documented moderate aortic regurgitation. Transoesophageal echocardiography displayed a rare case of quadricuspid aortic valve with three cusps of equal size and one larger cusp. The malformation was associated with severe aortic regurgitation.
  
  
  CONCLUSIONS
  Liberal use of transoesophageal echocardiography is often warranted if optimal display of valvular morphology is desired.
authors.affiliation: Dept of Clinical Sciences, Unit of Clinical Physiology and Nuclear Medicine, University Hospital MAS, Lund University, Malmö, Sweden. magnus.dencker@skane.se
authors.forename: Magnus
authors.initials: M
authors.lastname: Dencker
authors.forename: Martin
authors.initials: M
authors.lastname: Stagmo
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D003951:Diagnostic Errors / Q000517:prevention & control*; D004417:Dyspnea / Q000175:diagnosis / Q000209:etiology*; D004452:Echocardiography; D005188:False Negative Reactions; D005260:Female; D006801:Humans