The diagnosis of a non-stenotic bicuspid aortic valve.

Follow-up of a group of subjects in whom an aortic ejection sound was the only abnormal finding revealed a bicuspid aortic valve at necropsy or operation in 6 cases. High speed echophonocardiographic studies in 15 subjects with aortic stenosis and known to have bicuspid valves, showed the ejection sound to be exactly synchronous with final halting of the opening aortic valve cusps. Echocardiographic visualisation of the aortic valve from the apex, looking up the left ventricular outflow tract, showed valve echoes during systole indicating abnormal cusp configuration. This proved a more sensitive indicator of a bicuspid aortic valve than the finding of an eccentric aortic valve closure line. These findings were used to evaluate 37 subjects with the auscultatory finding of an isolated aortic ejection sound and the diagnosis of a non-stenotic bicuspid aortic valve was confirmed in 30. The usual cause of misdiagnosis was a sound associated with late tricuspid valve closure. The auscultatory finding of an aortic ejection sound, in the absence of other signs of aortic stenosis, indicates a non-stenotic, bicuspid aortic valve. Confirmation of aortic valvar origin of the sound can be provided by a simultaneous echophonocardiogram.