| RAS | rapid atrial stimulation; recurrent aphthous stomatitis; reflex activating stimulus; reliability, av... |
|---|---|
| REH | renin essential hypertension |
| REN | renal; renin |
| RR | radiation reaction; radiation response; rate ratio; rational recovery [group]; recovery room; relati... |
| RRR | regular rhythm and rate; renin release rate (or ratio) |