T-wave Offset Time (Reflex)
This test measures the electrical activity of your heart’s ventricles, specifically the timing of the T-wave offset, which can help assess heart rhythm and potential abnormalities in electrical conduction. It may be ordered as part of an automated reflex test following an electrocardiogram (ECG).
["This reflex test helps doctors evaluate heart health by checking how quickly the heart’s electrical signals reset after each heartbeat."]
Key facts at a glance
- LOINC
- 18515-7
- Short code
- T wave Offset Time RefB
- Synonyms
- T wave Offset Time RefB
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is a T-Wave Offset Time?
The T-wave is the final part of the electrical signal that causes your heart muscle to relax between beats. The T-wave offset time measures how long it takes for this signal to fully return to baseline. Abnormalities in this timing can indicate issues like heart strain, electrolyte imbalances, or other cardiac conditions.
Why Might This Test Be Ordered?
Your healthcare provider may order this reflex test if they suspect irregular heart rhythms, heart disease, or conditions affecting electrical activity in the heart. It is often used alongside an ECG to provide additional insights into heart function.
How Is the Test Performed?
This test is typically performed as part of an automated reflex process after an ECG. No additional blood, urine, or other samples are needed. The results are generated quickly based on the ECG readings.
What Do the Results Mean?
The results of the T-wave offset time reflex test help identify deviations in heart electrical activity. While this test alone may not provide a definitive diagnosis, it can signal the need for further evaluation, such as additional ECG readings or other cardiac tests.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
T-wave Offset Time (Auto-Reflex)
Frequently asked questions
How often do I need this test?
There are no specific numeric reference ranges provided for this reflex test because it is based on qualitative analysis of ECG findings. Your results will be reviewed by a healthcare professional to assess whether they fall within expected patterns for your heart’s electrical activity.
No special preparation is needed for this reflex test. It is performed as part of an ECG and does not require fasting, avoiding certain medications, or other restrictions. However, always follow your doctor’s instructions for any ECG-related preparations.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy