| MVOA | mitral valve orifice area |
|---|---|
| NCA | National Certification Agency; National Council on Aging; National Council on Alcoholism; neurocircu... |
| OSA | obstructive sleep apnea; Office of Services to the Aging; Optical Society of America; ovarian sectio... |
| PCA | para-chloramphetamine; parietal cell antibody; passive cutaneous anaphylaxis; patient care assistant... |
| POA | pancreatic oncofetal antigen; phalangeal osteoarthritis; preoptic area; primary optic atrophy |