| AOO | anodal opening odor; atrial asynchronous (competitive, fixed-rate) [pacemaker] |
|---|---|
| AR | absolute risk; accounts receivable; achievement ratio; actinic reticuloid [syndrome]; active resista... |
| ARC | accelerating rate calorimetry; acquired immunodeficiency syndrome-related complex; active renin conc... |
| ASFR | age-specific fertility rate |
| ASR | aldosterone secretion rate; antistreptolysin reaction |