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Left Ventricular Output Spiral CT (LV Output Measurement)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of blood your heart pumps through your left ventricle (the heart’s main pumping chamber) during each heartbeat, using a specialized CT scan technique. It helps assess how well your heart is functioning.

Quick summary

["This test helps doctors evaluate heart performance and identify potential issues like heart failure or other cardiac conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
8734-6
Short code
LV Output Spiral CT
Synonyms
LV Output Spiral CT
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct-spiral
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 Does This Test Measure?

The spiral CT scan creates detailed images of your heart’s blood flow and pumping function. It specifically measures the volume of blood ejected from your left ventricle with each heartbeat, known as cardiac output. This is done by tracking blood flow through the heart’s chambers and major blood vessels.

Why Is This Test Done?

Doctors may order this test if you have symptoms like shortness of breath, fatigue, or swelling that could indicate heart problems. It’s also used before surgeries, to monitor heart conditions, or to guide treatment plans for heart disease.

Preparation for the Test

No special preparation is usually needed. You may be asked to fast for a few hours before the test if contrast dye is used. Wear comfortable clothing and remove any jewelry or metal objects that could interfere with the scan.

What to Expect During the Test

You’ll lie down on a table that moves through a large, open CT scanner. A contrast dye may be injected to make blood vessels visible. The scan takes about 15–30 minutes, and you may feel a brief sensation of warmth or pressure from the dye.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

LV Output (Spiral CT)

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 1–3 business days, depending on your lab or hospital. Your healthcare provider will discuss them with you during your follow-up visit.
Is this test painful?
The scan itself is not painful, but you may feel a brief pinch from the needle when contrast dye is injected. Some people experience mild discomfort or warmth from the dye. If you have anxiety about scans, let your doctor know so they can provide reassurance or sedation options.
Can I eat or drink before this test?
If contrast dye is used, you may need to fast for a few hours beforehand. Always follow your doctor’s specific instructions for preparation. If no fasting is required, you can eat and drink normally.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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