| ARP | absolute refractory period; American Registry of Pathologists; anticipated recovery path; apolipopro... |
|---|---|
| ART | absolute retention time; Accredited Record Technician; acoustic reflex test; algebraic reconstructio... |
| ATA | alimentary toxic aleukia; American Thyroid Association; aminotriazole; antithymic activity; antithyr... |
| h | Greek letter eta; absolute viscosity |
| M3 | absolute dullness; myelocyte at the 3rd stage of maturation |