| RAFW | right atrial free wall |
|---|---|
| RFI | radiofrequency interference; recurrence-free interval; renal failure index |
| RFS | relapse-free survival; renal function study; rotating frame spectroscopy |
| SFFA | serum free fatty acid |
| SFM | Schimmelpenning-Fuerstein-Mims [syndrome]; serum-free medium; solution-focused management |