TOF
Abbreviation with 3 meanings
| Stands for | Tetralogy of Fallot |
|---|---|
| Meanings | 3 |
| Categories | Medical, Science & Engineering |
TOF has three meanings. The most common are Tetralogy of Fallot (cardiology) and Train-of-four (anesthesia); it can also stand for Time of flight.
Meanings of TOF at a glance
| # | TOF stands for | Context |
|---|---|---|
| 1 | Tetralogy of Fallot | Medical › Cardiology |
| 2 | Train-of-four | Medical › Anesthesia |
| 3 | Time of flight | Science & Engineering › Physics |
1. Tetralogy of Fallot
Medical · Cardiology Abbreviations
Most common cyanotic congenital heart defect, combining four features: ventricular septal defect, pulmonary stenosis, an overriding aorta and right ventricular hypertrophy. Babies may have "tet spells," sudden episodes of deep cyanosis, and complete surgical repair is usually done in the first year of life.
Example: Infant with a boot-shaped heart on chest x-ray; echo confirms TOF, repair planned at 4 months.
Named for French physician Étienne-Louis Arthur Fallot, who described it in 1888. Older children with unrepaired TOF instinctively squat, which raises systemic resistance and reduces right-to-left shunting. Repaired adults commonly develop pulmonary regurgitation and need valve replacement later. The 1944 Blalock-Taussig shunt, an early palliative operation for TOF, was one of the founding procedures of heart surgery.
2. Train-of-four
Medical · Anesthesia Abbreviations
Nerve stimulation test that delivers four electrical pulses at 2 Hz, usually to the ulnar nerve, and counts or measures the resulting thumb twitches to gauge neuromuscular blockade. A train-of-four ratio (fourth twitch divided by first) of at least 0.9 indicates adequate recovery for extubation.
Example: TOF 0/4 before reversal; after sugammadex the TOF ratio is 0.98.
Counting twitches by sight or feel cannot reliably detect ratios below 0.9, so a 2023 ASA guideline recommends quantitative monitors using acceleromyography or electromyography. In cardiology TOF means tetralogy of Fallot, a congenital heart defect.
3. Time of flight
Science & Engineering · Physics Abbreviations
Measurement of how long a particle, ion or light pulse takes to travel a known distance, used to determine its speed, mass or the distance to a surface. Time-of-flight mass spectrometers sort ions by arrival time, and TOF depth cameras in phones and robots time reflected infrared light.
Example: The phone's TOF sensor measures depth by timing infrared pulses bounced off the face.
In mass spectrometry, lighter ions reach the detector first because all ions receive the same kinetic energy. Particle physics experiments use TOF detectors to tell particles of the same momentum apart. Also written ToF.
Related abbreviations
More cardiology abbreviations
- TGA – Transposition of the great arteries
- TIMI – Thrombolysis in Myocardial Infarction
- TnI – Troponin I
- TnT – Troponin T
- TR – Tricuspid regurgitation
- TTE – Transthoracic echocardiogram
- TTS – Takotsubo syndrome
- UA – Unstable angina
See all 229 cardiology abbreviations →
More anesthesia abbreviations
- ASA – American Society of Anesthesiologists physical status classification
- BIS – Bispectral index
- CICO – Can't intubate, can't oxygenate
- CSE – Combined spinal-epidural
- DL – Direct laryngoscopy
- eFONA – Emergency front-of-neck access
- ESP – Erector spinae plane (block)
- EtCO2 – End-tidal carbon dioxide
See all 34 anesthesia abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.