JaxCC1 project protocol for procedure: EKG

Multisystem phenotyping of 18 Collaborative Cross strains   (2018)

The Jackson Laboratory


See JAX Pipeline on the IMPC website for order of tasks for all mice tested

Project protocol: Electrocardiogram (ECG)


Electrocardiography is used to record the electrical activity of the heart over a period of time in a conscious mouse.

Study design

  • Paradigm: Baseline study
  • Panel: Collaborative Cross
  • Number of strains: 18
  • Sex: Both
  • Age: 10-12 wks
  • Sample size: Seven mice per sex from at least two litters
  • Number of cohorts: 1


    Step Description Equipment Data collected
    1 Record electrical activity of the heart Electrocardiogram Heart rate, duration of intervals, dispersion, amplitudes

    Equipment, software and supplies




    1. The lead plates are to be snapped into place onto the top of the pre-amplifier tower. The covering is removed to reveal three gel coated pads surrounded by a sticking plate. The plate is covered with the extra cover in the package.
    2. Turn on the combined amplifier and the pre-amplifier tower.
    3. Double click the icon ECG acquisition on the acquisition computer.
    4. Open the ECG set up file (for default settings).
    5. Place mouse on pad, lowering the red acrylic cubby to surround the mouse on 3 sides discouraging escape.
    6. Press start.
    7. After the desired acquisition time (5-10 min) stop the reading.
    8. Highlight sections with good readings and save the data.
    9. Analyze the data according to manufacturer's protocol.


    Data QC: Raw data are stored until outlier detection and other QA/QC procedures are complete.



    LIMS field name MPD variable name Description Units Series Primary measurement Series order MPD computed Calculation Method Data type
    Number of signals -                  


    HR heart rate, beats per min n/min           ECG Float
    CV HR_CV heart rate coefficient of variation (signal intensity) %           ECG Float
    RR RR duration of RR interval ms           ECG Float
    PQ PQ duration of PQ interval ms           ECG Float
    PR PR duration of PR interval ms           ECG Float
    QRS QRS duration of QRS interval ms           ECG Float
    ST ST duration of ST interval ms           ECG Float
    QTc QTc duration of QTC interval, calculated by dividing QT interval by square root of preceding RR interval ms           ECG Float
    HRV HR_V heart rate variability, mean of differences between sequential beats; beats per min n/min           ECG Float
    QT dispersion QT_dispersion QT dispersion, measured as inter-lead variability of QT intervals ms           ECG Float
    QTc dispersion


    QTc dispersion, calculated as rate-corrected QT dispersion ms           ECG Float
    Mean SR amplitude SR_amplitude mean SR amplitude, mean amplitude of signal measured from signal minimum line to peak of QRS mV           ECG Float
    Mean R amplitude R_amplitude mean R amplitude, mean amplitude of signal measured from isoelectric line to peak of QRS mV           ECG Float
    rMSSD rMSSD root mean square of successive differences of neighboring RR intervals ms Yes         ECG Float
    pNN5(6>ms) pNN50 proportion of number of pairs of successive beat-to-beat intervals that exceed 50 ms (6>ms) %           ECG Float

    Experimental and technical parameters

    Equipment name Electrocardiogram (ECG)
    Equipment manufacturer Mouse Specifics, Inc.
    Equipment model ECGenie
    Anesthesia None