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

Project protocol: Electrocardiogram (ECG)

• Introduction
• Study design
• Workflow
• Equipment, software and supplies
• Procedure
• Measurements
• Experimental and technical parameters

Introduction

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

Workflow

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

Equipment, software and supplies

• Electrocardiogram: ECGenie (Mouse Specifics, Inc.) [See Experimental and technical parameters]

 

 

Procedure

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.

 

Measurements

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