Published: March 27th, 2021
Using simultaneous video-EEG-ECG-oximetry-capnography, we developed a methodology to evaluate the susceptibility of rabbit models to develop provoked arrhythmias and seizures. This novel recording system establishes a platform to test the efficacy and safety of therapeutics and can capture the complex cascade of multi-system events that culminate in sudden death.
Patients with ion channelopathies are at a high risk of developing seizures and fatal cardiac arrhythmias. There is a higher prevalence of heart disease and arrhythmias in people with epilepsy (i.e., epileptic heart.) Additionally, cardiac and autonomic disturbances have been reported surrounding seizures. 1:1,000 epilepsy patients/year die of sudden unexpected death in epilepsy (SUDEP). The mechanisms for SUDEP remain incompletely understood. Electroencephalograms (EEG) and electrocardiograms (ECG) are two techniques routinely used in the clinical setting to detect and study the substrates/triggers for seizures and arrhythmias. While many studies and descriptions of this methodology are in rodents, their cardiac electrical activity differs significantly from humans. This article provides a description of a non-invasive method for recording simultaneous video-EEG-ECG-oximetry-capnography in conscious rabbits. As cardiac electrical function is similar in rabbits and humans, rabbits provide an excellent model of translational diagnostic and therapeutic studies. In addition to outlining the methodology for data acquisition, we discuss the analytical approaches for examining neuro-cardiac electrical function and pathology in rabbits. This includes arrhythmia detection, spectral analysis of EEG and a seizure scale developed for restrained rabbits.
Electrocardiography (ECG) is routinely used in the clinical setting to assess the dynamics of cardiac electrical conduction and the electrical activation-recovery process. ECG is important for detecting, localizing, and assessing the risk of arrhythmias, ischemia, and infarctions. Typically, electrodes are affixed to the patient's chest, arms, and legs in order to provide a three-dimensional view of the heart. A positive deflection is produced when the direction of myocardial depolarization is toward the electrode and a negative deflection is produced when the direction of myocardial depolarization is away from the electrode. Electrographic components of the cardi....
All experiments were carried out in accordance with the National Institutes of Health (NIH) guidelines and Upstate Medical University Institutional Animal Care and Use Committee (IACUC). In addition, an outline of this protocol is provided in Figure 1.
1. Preparing recording equipment
The method described above is capable of detecting abnormalities in the electrical conduction system of the brain and the heart as well as respiratory disturbances. A data acquisition software is used to assess the ECG morphology and detect any abnormal heart rates, conduction disturbances, or ECG rhythms (atrial/ventricular ectopic beats, and brady-/tachy-arrhythmias) (Figure 6). In addition to visualizing the ECG morphology, the traces are analyzed to quant.......
This experimental setup facilitates detailed simultaneous video-EEG-ECG-oximetry-capnography recordings and analyses in rabbits, particularly in models of cardiac and/or neuronal diseases. The results of this article show that this method is capable of detecting seizures and arrhythmias and differentiating them from electrographic artifacts. Expected results were obtained when giving rabbits a proconvulsant, which induced seizures. The data obtained from the video-EEG recordings were able to be further analyzed to differ.......
|0.9% Sodium Chloride Irrigation, USP - Flexible Container
|10cc Luer Lock syringe with 20G x 1" Needle
|Used as a flush after drug injection
|4x4 gauze sponges
|Rolled in a tube to splint ear with angiocatheter
|Vehicle for oral medications
|Agent known to prolong the QT interval
|13mm 35-degree bent (0.4 mm diameter) subdermal pin electrodes
|5-twist 13mm straight (0.4mm diameter) subdermal pin electrodes
|Swartz Center for Computational Neuroscience
|Can perform spectral analysis of EEG
|Adapter for connecting the camera to the computer
|Contains pentobarbital sodium and phenytoin sodium, controlled substance
|Reduces pressure applied to the neck of small rabbits by the restrainer in order to prevent the adverse cardiorespiratory effects of neck compression
|Heparin Lock Flush
|To maintain patency of angiocatheter
|Facilitates recordings in the dark
|LabChart Pro (2019, Version 8.1.16)
|JELCO PROTECTIV Safety I.V. Catheters, 25 gauge
|Used to catherize marginal ear vein
|MATLAB (R2019b, Update 5)
|Required to run EEGLAB
|Recording of audible manifestions of seizures
|Micropore Medical Tape, Paper, White
|Used to secure wires and create ear splint
|Acquisition and review software
|Pentylenetetrazol (1 - 10 mg/kg always in 1mL volume)
|Dilutions prepared in saline
|Stimulator to control frequency, delay, duration, intensity of the light pulses
|Plastic wire organizer / bundler
|Bundle wires to cut down on noise
|PS 22 Photic Stimulator
|Strobe light with adjustable flash frequency, delay, and intensity
|Prevents small rabbits from kicking their hind legs and causing spinal injury
|Amplifier / digitizer
|Quantum HeadBox Amplifier
|64-pin breakout box
|Various size rabbit restrainers are available. 6" x 18" x 6" in this study.
|Rubber pad (booster)
|Raises small rabbits up in the restrainer to prevent neck compression
|SpO2 ear clip
|SpO2 sensor adapter
|SRG-X120 1080p PTZ Camera with HDMI, IP & 3G-SDI Output
|Terumo Sur-Vet Tuberculin Syringe 1cc 25G X 5/8" Regular Luer
|Used to inject intravenous medications
|Veterinary Injection Plug Luer Lock
|Injection plug for inserting the needle for intravenous medication
|Webcol Alcohol Prep, Sterile, Large, 2-ply
|To prepare ear vein before catheterization
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