| AR | absolute risk; accounts receivable; achievement ratio; actinic reticuloid [syndrome]; active resista... |
|---|---|
| ARAO | angiographic area of right anterior oblique projection |
| ARV | acquired immunodeficiency syndrome-related virus; anterior right ventricle; avian reovirus |
| ASA | acetylsalicylic acid; active systemic anaphylaxis; Adams-Stokes attack; American Society of Anesthes... |
| asc | ascending; anterior subcapsular |