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R-wave amplitude (electrocardiogram)

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

This test measures the height of the R-wave on an electrocardiogram (ECG), a recording of your heart’s electrical activity. It helps assess heart rhythm, conduction speed, and potential structural changes in the heart.

Quick summary

["The R-wave amplitude can indicate heart health and electrical activity patterns."]

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

Key facts at a glance

LOINC
10015-6
Short code
R' wave Amp L-III
Synonyms
R' wave Amp L-III
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 an R-Wave Amplitude Test Used For?

Doctors use R-wave amplitude measurements to evaluate heart function, particularly in diagnosing conditions like heart block, myocardial infarction (heart attack), or assessing the effects of certain medications or treatments. It may also help monitor heart rhythm irregularities or detect early signs of heart disease.

How Is This Test Performed?

An R-wave amplitude test is typically part of a standard ECG. You’ll lie down on an exam table while electrodes are placed on your chest, arms, and legs. The test captures your heart’s electrical signals over 10–15 seconds, and the R-wave height is measured from the baseline to the peak of the R-wave on the recorded tracing.

What Does an R-Wave Amplitude Result Mean?

The results are interpreted by a healthcare provider based on your overall ECG pattern and clinical context. Abnormal R-wave amplitudes (either too high or too low) may suggest changes in heart tissue, such as scar tissue from a previous heart attack, or differences in heart conduction pathways.

When Might You Need This Test?

You may receive an R-wave amplitude test if you have symptoms like chest pain, palpitations, or dizziness; if you’ve had a heart attack or other heart-related issues; or if your doctor is monitoring a known heart condition. It’s also sometimes included in routine cardiac evaluations.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

ECG R-wave height

Frequently asked questions

Why is the R-wave amplitude important in diagnosing heart conditions?
R-wave amplitude can help identify specific areas of the heart affected by conditions like myocardial infarction (heart attack), where damaged heart tissue may alter electrical signals. For example, a reduced R-wave amplitude in certain leads may indicate scar tissue or fibrosis, while changes in amplitude across leads can help pinpoint the location of an infarction or assess the progression of a heart condition.
How does R-wave amplitude differ from other ECG measurements?
Unlike other ECG measurements (e.g., heart rate, QRS duration), R-wave amplitude focuses solely on the height of the R-wave, which can be more sensitive to localized changes in heart tissue. It’s often used alongside other ECG features to provide a comprehensive view of heart function and electrical activity.
Can lifestyle changes affect R-wave amplitude?
While R-wave amplitude is primarily a measure of electrical activity captured during an ECG, certain lifestyle factors—such as extreme physical exertion, dehydration, or certain medications—might influence heart rhythm or conduction. However, R-wave amplitude itself is not directly affected by lifestyle changes unless they directly impact heart tissue or electrical pathways.
  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