| SNRTd | sinus node recovery time, direct measuring |
|---|---|
| SNRTi | sinus node recovery time, indirect measuring |
| SNS | Senior Nursing Sister; Society of Neurological Surgeons; sympathetic nervous system |
| SNSA | seronegative spondyloarthropathy |
| SNST | sciatic nerve stretch test |
| SNT | sinuses, nose, and throat |
| SNU | skilled nursing unit |
| SNV | spleen necrosis virus |
| SNW | slow negative wave |