| AEI | arbitrary evolution index; atrial emptying index |
|---|---|
| AERP | antegrade effective refractory period; atrial effective refractory period |
| AFib | atrial fibrillation |
| AFL | antifibrinolysin; artificial limb; atrial flutter |
| AHR | antihyaluronidase reaction; Association for Health Records; atrial heart rate |