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R-wave amplitude (ECG)

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

This test measures the height of the R-wave on an electrocardiogram (ECG), which reflects electrical activity in your heart’s right ventricle. It’s often used alongside other ECG measurements to assess heart function.

Quick summary

["Your R-wave height can help doctors evaluate heart rhythm and structure."]

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

Key facts at a glance

LOINC
9991-1
Short code
R wave Amp L-V1
Synonyms
R wave Amp L-V1
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?

The R-wave is the first positive deflection (peak) on an ECG tracing, representing depolarization of the heart’s right ventricle. Its amplitude varies depending on heart position, size, and lead placement. In standard leads (e.g., V1–V6), a normal R-wave grows progressively larger from lead V1 toward V6, reflecting the heart’s electrical progression.

Why Is It Measured?

Measuring R-wave amplitude helps diagnose conditions like bundle branch blocks (e.g., right bundle branch block), myocardial infarction (heart attack), or structural heart abnormalities. It may also be used to monitor heart disease progression or response to treatment.

How Is It Done?

Your ECG is recorded using electrodes placed on your chest, arms, and legs. The R-wave amplitude is measured from the ECG tracing in specific leads (e.g., V1–V6). A healthcare provider interprets the results in relation to your overall ECG pattern.

What Can Affect Results?

Several factors can influence R-wave amplitude, including body position (e.g., sitting vs. lying down), electrode placement errors, or technical issues during the ECG recording. Certain medications (e.g., beta-blockers) or heart conditions (e.g., hypertrophy) may also alter it.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

R-wave height

Frequently asked questions

How does R-wave amplitude relate to heart health?
R-wave amplitude can indicate abnormalities in heart conduction pathways. For example, a very small R-wave in V1 might suggest a right bundle branch block, while inconsistent amplitudes across leads could signal structural heart disease. However, it’s typically interpreted alongside other ECG features for a complete assessment.
What does an abnormal R-wave mean?
An abnormal R-wave (e.g., too small, too large, or inconsistent) may warrant further evaluation, such as additional ECGs, imaging (e.g., echocardiogram), or cardiac testing. Always discuss results with your doctor, as they’ll consider your full medical history and other test results.
Is R-wave testing common?
Yes, R-wave amplitude is routinely assessed during routine ECGs. It’s not a standalone test but part of a comprehensive evaluation of your heart’s electrical activity. Your doctor may order it if they suspect heart rhythm issues or structural problems.
  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