: Q wave, Electrocardiogram
: A Q wave is a downward deflection seen on an electrocardiogram (ECG) that can reflect the electrical activity of the heart muscle. Certain patterns of Q waves may suggest prior heart muscle injury.
[": Q waves are an ECG finding that can help your clinician assess your heart's electrical health and history."]
Key facts at a glance
- LOINC
- 8630-6
- Short code
- Q wave Dpth Lead
- Synonyms
- Q wave Dpth Lead
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- CPT
- 85610
- SNOMED
- 396252006
- 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 a Q Wave Is
: An electrocardiogram records the heart's electrical signals as waveforms. A Q wave is a small downward (negative) deflection that can appear at the start of the main heartbeat complex. Its size and shape are interpreted together with the rest of the ECG tracing.
: How the Test Is Done
: The ECG is painless and quick. Small electrodes are placed on your chest, arms, and legs while a machine records your heart's electrical activity. You usually lie still for a short time, and no special preparation is typically needed.
: What the Result Means
: Your clinician looks at Q waves along with many other ECG features. A Q wave on its own does not diagnose a condition; it must be interpreted in the context of your symptoms, medical history, and other test results.
: Why It May Be Ordered
: An ECG may be ordered for chest pain, palpitations, shortness of breath, a known heart condition, or as part of a routine checkup. It helps assess the heart's rhythm and electrical patterns.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
: Q waves can sometimes reflect prior injury to heart muscle, but they can also appear for other reasons. Because interpretation depends on many factors, your clinician will use the full ECG and your clinical picture to decide what, if anything, a Q wave means for you.
Short name
: Q Wave on ECG
Frequently asked questions
: Does having a Q wave mean I had a heart attack?
: Is an ECG painful?
: Do I need to prepare for an ECG?
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