| A2 | aortic second sound |
|---|---|
| A2-OS | aortic second sound, opening snap |
| ACS | acrocallosal syndrome; acrocephalosyndactyly; acute chest syndrome; acute confusional state; Alcon C... |
| AES | acetone-extracted serum; American Electroencephalographic Society; American Encephalographic Society... |
| AOS | American Ophthalmological Society; American Otological Society; anodal opening sound; anterior [o]es... |