Cette recherche a été financée par une subvention de l&#39;citoyens américains pour la recherche en épilepsie (CURE) pour SLB.

<p class="jove_title"&gt; 1. Matériaux de construction</p&gt;<ol&gt;<li&gt; Un cathéter jugulaire est construit à partir d&#39;un morceau (100 mm) de tubes en polyéthylène PE-50, biseautés à une extrémité, puis rempli avec de l&#39;héparine salines (50 U d&#39;héparine / ml solution saline).</li&gt;<li&gt; Les électrodes ECG sont construits à partir de deux longueurs 100 mm de fil d&#39;argent isolé (30AWG). Une extrémité des deux fils est dépouillé et soudé à un microconnector, et l&#39;isolation est tordu pour former un troisième fil qui est utilisé comme terrain. Cinq mm d&#39;isolant est dépouillé de l&#39;extrémité distale des fils et jetés.</li&gt;</ol&gt;<p class="jove_title"&gt; 2. L&#39;implantation de cathéter veineux jugulaire</p&gt;<ol&gt;<li&gt; Anesthetize l&#39;animal par administration d&#39;uréthane, ip (1,2 g / kg).</li&gt;<li&gt; Vérifiez régulièrement (intervalles de 10 min) profondeur de l&#39;anesthésie en évaluant la réponse de retrait pédale et / ou les réflexes oculaires. Si nécessaire, compléter l&#39;anesthésie.</li&gt;<li&gt; Après l&#39;animal est dans le plan approprié de l&#39;anesthésie, raser le côté droit du cou de la clavicule au menton.</li&gt;<li&gt; Faire une incision longitudinale (10-15 mm) dans la peau au-dessus de l&#39;artère carotide et ouvrir l&#39;incision.</li&gt;<li&gt; En utilisant des techniques dissection, la propagation du muscle sous-jacent pour localiser et isoler la veine jugulaire droite.</li&gt;<li&gt; Placez deux morceaux de soie chirurgicale (# 2) sous la veine jugulaire, et la position des sutures au niveau des portions plus rostrale et caudale de l&#39;incision. Tie la ligature rostrale de mettre fin à circuler à travers la veine.</li&gt;<li&gt; Retract la ligature caudale de soulever le navire au large des tissus sous-jacents et de faire une petite coupure. Ensuite, insérez l&#39;extrémité biseautée de l&#39;héparine-remplie (50 U / ml de sérum physiologique) du cathéter PE-50 en polyéthylène (100 mm de longueur), et de faire avancer la pointe d&#39;environ 8 mm au niveau de l&#39;oreillette droite.</li&gt;<li&gt; Afin de sécuriser le cathéter, une cravate de la ligature caudale à la fois le navire et le cathéter. Enfin, fermer la plaie avec des pinces ou des plaies soit suture.</li&gt;<li&gt; Au cours de l&#39;implantation du cathéter, l&#39;extrémité exposée est soit serré avec une pince hémostatique ou branché pour empêcher le reflux du sang avant l&#39;attachement à une pompe à perfusion.</li&gt;</ol&gt;<p class="jove_title"&gt; 3. Implanter des électrodes CG</p&gt;<ol&gt;<li&gt; Placez l&#39;animal sur son dos et se raser la poitrine.</li&gt;<li&gt; Pour le placement des électrodes, faire deux incisions longitudinales (≈ 10 mm), un dans le coin supérieur droit et un dans les quadrants inférieurs gauche de la poitrine, et sans la peau recouvrant d&#39;exposer les muscles thoraciques.</li&gt;<li&gt; Suture l&#39;un des exposés de 5 mm extrémités des électrodes d&#39;argent-fil dans les muscles thoraciques dans chacune des zones exposées, et la place l&#39;électrode de masse sous-cutanée.</li&gt;<li&gt; Fermer les incisions avec des clips de la plaie et de brancher le microconnector dans le dispositif d&#39;enregistrement.</li&gt;<li&gt; Enveloppez l&#39;animal sans serrer dans une serviette afin de maintenir la température du corps pendant la procédure.</li&gt;</ol&gt;<p class="jove_title"&gt; 4. Enregistrement ECG</p&gt;<ol&gt;<liEnregistrements&gt; sont faites en utilisant un système d&#39;acquisition de données Powerlab et Macintosh ou matériel informatique / logiciels similaires (amplifié, 50X; filtrée, 1-1000 Hz).</li&gt;<li&gt; Après une période de 20-30 minutes d&#39;équilibration, d&#39;enregistrer l&#39;ECG pendant 20 min.</li&gt;</ol&gt;<p class="jove_title"&gt; 5. Induire arythmies ventriculaires</p&gt;<ol&gt;<li&gt; Joindre le cathéter jugulaire à une seringue à distance placée dans une pompe à perfusion programmable.</li&gt;<li&gt; Initier la perfusion aconitine à un taux de délivrer une dose constante de 5 ug / kg / min pendant 7 minutes.</li&gt;<liLa fibrillation&gt; ventriculaire après ou à la fin de la période de perfusion, euthanasier l&#39;animal en utilisant une procédure approuvée.</li&gt;</ol&gt;<p class="jove_title"&gt; 6. L&#39;analyse de l&#39;ECG</p&gt;<ol&gt;<li&gt; L&#39;intervalle QT représente la durée totale de l&#39;activité ventriculaire électrique. Fig. 1 montre un enregistrement de modèle d&#39;ECG et de la durée de l&#39;intervalle QT. Calculer le temps moyen entre le début de l&#39;onde Q et la fin de l&#39;onde T pour toutes les battements enregistrés sur un intervalle de cinq minutes a obtenu pendant la période de 20 minutes d&#39;enregistrement.</li&gt;<li&gt; Pour corriger l&#39;intervalle QT des différences dans la fréquence cardiaque (QTc), utilisez la formule de Bazett, QTc = QT / (RR)<sup&gt; ½</sup&gt;, Où RR est l&#39;intervalle moyen entre deux battements. L&#39;intervalle RR est calculé comme étant la durée entre successives ondes Q obtenues au cours de la période analysée.</li&gt;<li&gt; La dispersion du QT (QTD) est calculé en soustrayant du QT minimale de l&#39;intervalle QT maximum enregistré pour chaque animal.</li&gt;</ol&gt;<p class="jove_title"&gt; 7. Analyse de la variabilité du rythme cardiaque</p&gt;<ol<liLogiciels&gt; (c&#39;est à dire LabChart 7, ADInstruments, Inc) qui analysent la variabilité des intervalles RR obtenus pendant la période d&#39;analyse sont utilisées pour le calcul automatisé de variance à la fois temporelle et / ou spectrale de la fréquence cardiaque.</li</ol&gt;<p class="jove_title"&gt; 8. Analyse de sensibilité à des arythmies ventriculaires</p&gt;<ol<li&gt; Calculer le temps de latence entre le début de la perfusion de l&#39;aconitine à la contraction ventriculaire prématurée première (PVC, fig. 2, partie 1), la tachycardie ventriculaire (TV, fig, 2, Groupe 2) et une fibrillation ventriculaire (FV, fig. 2 Panel 3 ).</li</ol&gt;<p class="jove_title"&gt; 9. Les résultats représentatifs</p&gt;<p class="jove_content"&gt; Fig. 3 illustre une mesure de la VRC dans le domaine spectral (racine quadratique moyenne de l&#39;écart-type de l&#39;intervalle RR, RMSSD) chez les rats témoins et chez les animaux qui ont subi une SE, une semaine avant le test. Cette mesure de VRC, ce qui représente un changement de contrôle de la fonction cardiaque parasympathique<sup&gt; 26</sup&gt;, Est significativement diminuée chez les animaux après état de mal épileptique. Fig. 4 montre que les deux l&#39;intervalle QT corrigé (QTc, partie A) et la dispersion du QT (QTD, partie B) sont significativement augmentés de deux semaines après SE<sup&gt; 27</sup&gt;. Pris ensemble, ces données prédisent que SE augmente le risque d&#39;arythmie ventriculaire. Cette prédiction est confirmée par les résultats que les périodes de perfusion aconitine nécessaire pour induire l&#39;arythmie expérimentale (PVC, VT, VF) observés dans ces études étaient significativement plus petits chez les animaux après SE (fig. 5)<sup&gt; 27</sup&gt;.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig1.jpg" alt="figure 1" /<br /<strong&gt; Figure 1.</strong&gt; Modèle ECG d&#39;enregistrement d&#39;un rythme cardiaque normal montrant P, QRS et des ondes T. L&#39;intervalle QT est calculé comme le temps entre les lignes pointillées.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig2.jpg" alt="figure 2" /<br /<strong&gt; Figure 2. Panel 1)</strongContractions&gt; extrasystoles ventriculaires (ESV) sont isolés des contractions des ventricules (B) qui se produisent entre deux battements normaux (A). Enregistrements en PVC sont caractérisés par l&#39;absence d&#39;ondes P et T.<strongPanneau de configuration&gt; 2</strongLa tachycardie ventriculaire&gt; (VT) est une série de contractions ventriculaires multiples (C) qui se produisent sans battements intervenant normale (A).<strongPanneau de configuration&gt; 3</strongLa fibrillation ventriculaire&gt; (VF) est le manque de rythme discernable et aucune association entre le QRS et des ondes P (D).</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig3.jpg" alt="figure 3" /<br /<strong&gt; Figure 3.</strong&gt; La racine quadratique moyenne de l&#39;écart-type (RMSSD; ms) de l&#39;intervalle entre les battements cardiaques observés chez les rats témoins et chez les animaux subissant état de mal épileptique (SE) 1 semaine avant le test. ** P &lt;0,01 par rapport au témoin.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig4.jpg" alt="figure 4" /<br /<strong&gt; Figure 4.</strong&gt; Mean l&#39;intervalle QT corrigé (Groupe A) et la dispersion du QT (Groupe B), calculée à partir d&#39;enregistrements ECG provenant d&#39;animaux de contrôle (Cont) et de rats subissant état de mal épileptique (SE) deux semaines avant le test. * P &lt;0,05 par rapport à Cont. (Metcalf et al., Am. J. Physiol. Cœur et Circ 2009, Am Soc Physiol, utilisé avec la permission de<sup&gt; 27</sup&gt;).</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig5.jpg" alt="figure 5" /<br /<strong&gt; Figure 5.</strong&gt; Latences (s) entre le début de la perfusion aconitine et la contraction premier extrasystoles ventriculaires (PVC), la tachycardie ventriculaire (TV), et la fibrillation ventriculaire (FV) chez les animaux témoins (suite) et les rats subissant état de mal épileptique (SE) deux semaines avant à des tests. * P &lt;0,05, ** p &lt;0,01 par rapport à Cont. (Metcalf et al., Am. J. Physiol. Cœur et Circ 2009, Am Soc Physiol, utilisé avec la permission de<sup&gt; 27</sup&gt;).</p&gt;

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Deux aspects des procédures décrites sont d&#39;une importance critique. Premièrement, le taux d&#39;administration aconitine au cœur doit être équivalente dans les animaux. Cela nécessite de placement cohérente des conseils cathéter veineux jugulaire par rapport au cœur, et l&#39;ajustement attentif de la vitesse de perfusion. Le taux d&#39;accouchement à l&#39;aconitine cœurs doivent être égaux afin d&#39;évaluer correctement la survenue d&#39;arythmies ventriculaires par rapport à la sensibilité alt?...

methods for ecg evaluation of indicators of cardiac risk, and susceptibility to aconitine-induced arrhythmias in rats following status epilepticus

Lethal arythmies cardiaques contribuent à la mortalité dans un certain nombre de conditions pathologiques. Plusieurs paramètres obtenus à partir d&#39;un non-invasive, électrocardiogramme facilement obtenue (ECG) sont établis, bien validé les indicateurs pronostiques du risque cardiaque chez les patients souffrant d&#39;un certain nombre de cardiomyopathies. Augmentation du rythme cardiaque, diminution de la variabilité du rythme cardiaque (HRV), et augmenté la durée et la variabilité de l&#39;activité électrique cardiaque ventriculaire (intervalle QT) sont autant de signes d&#39;amélioration du risque cardiaque 1-4. Dans les modèles animaux, il est utile de comparer ces ECG variables dérivées et la susceptibilité à l&#39;arythmie induite expérimentalement. La perfusion intraveineuse de l&#39;agent de l&#39;aconitine arythmogène a été largement utilisé pour évaluer la susceptibilité à l&#39;arythmie dans une gamme de conditions expérimentales, y compris les modèles animaux de dépression et d&#39;hypertension 5 6, 7 et après un exercice d&#39;exposition aux polluants atmosphériques 8, ainsi que la détermination de l&#39;anti-arythmique l&#39;efficacité des agents pharmacologiques 9,10. Il faut noter que la dispersion du QT chez les humains est une mesure de la variation de l&#39;intervalle QT à travers le jeu complet de cordons d&#39;une norme de l&#39;ECG 12 dérivations. Par conséquent, la mesure de la dispersion du QT de l&#39;ECG 2-plomb chez le rat décrite dans ce protocole est différent de celui calculé à partir de enregistrements ECG humain. Cela représente une limitation dans la traduction des données obtenues à partir de rongeurs à la médecine clinique humaine. État de mal épileptique (SE) est une saisie ou une série de crises récurrentes en permanence de plus de 30 min 11,12 11,12, et les résultats de la mortalité dans 20% des cas 13. Beaucoup de personnes survivent à la SE, mais meurent dans les 30 jours 14,15. Le mécanisme (s) de cette mortalité retardée n&#39;est pas entièrement comprise. Il a été suggéré que des arythmies ventriculaires mortelles contribuer à beaucoup de ces décès 14-17. En plus de SE, les patients présentant des convulsions récurrentes spontanément, l&#39;épilepsie-dire, sont à risque de mort prématurée soudain et inattendu associé à l&#39;épilepsie (MSIE) 18. Comme avec SE, les mécanismes précis de médiateur MSIE ne sont pas connus. Il a été proposé que des anomalies ventriculaires et les arythmies résultant apporter une contribution significative 18-22. Pour étudier les mécanismes de saisie liés à la mort cardiaque, et l&#39;efficacité des thérapies cardio, il est nécessaire d&#39;obtenir à la fois des indicateurs ECG dérivés de risque et d&#39;évaluer la susceptibilité à l&#39;arythmie cardiaque dans des modèles animaux de troubles épileptiques 23-25. Nous décrivons ici les méthodes d&#39;implantation d&#39;électrodes ECG chez le rat Sprague-Dawley de laboratoire (Rattus norvegicus), suite au SE, la collecte et l&#39;analyse des enregistrements ECG, et l&#39;induction d&#39;une arythmie pendant la perfusion iv de l&#39;aconitine. Ces procédures peuvent être utilisées pour déterminer directement les relations entre l&#39;ECG dérivés des mesures de l&#39;activité électrique cardiaque et la susceptibilité aux arythmies ventriculaires chez des modèles de rats de troubles épileptiques, ou toutes pathologies associées à un risque accru de mort subite cardiaque.

Watch this Scientific Journal Video about Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus at JoVE.com

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Techniques de mesure de l&#39;activité électrique du cœur par l&#39;électrocardiogramme (ECG), et l&#39;analyse des facteurs de risque cardiaque et de la susceptibilité aux arythmies suivantes état de mal épileptique (SE) chez le rat sont décrits.

Méthodes d&#39;évaluation de l&#39;ECG d&#39;indicateurs de risque cardiaque, et la susceptibilité à l&#39;aconitine arythmies induites chez le rat après Etat de mal épileptique

Lethal cardiac arrhythmias contribute to mortality in a number of pathological conditions. Several parameters obtained from a 
non-invasive, easily ...

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Research

JoVE Journal

Medicine

17.6K vues.  University of Utah. Techniques de mesure de l'activité électrique du cœur par l'électrocardiogramme (ECG), et l'analyse des facteurs de risque cardiaque et de la susceptibilité aux arythmies suivantes état de mal épileptique (SE) chez le rat sont décrits.

Vidéo: Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50&#8211;60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage.

We describe a stepwise procedure for creating pressure overload and left ventricular hypertrophy in Wistar rats by constriction of the ascending aorta using a small metallic clip. This model is extensively used for studying remodeling changes during cardiac hypertrophy and for identifying and evaluating strategies for regression of such changes.

Aortique ascendant constriction chez les rats pour la création de la surcharge de pression hypertrophie cardiaque Modèle

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart ...

Recherche

Médecine

Early Detection of Drug-Induced Renal Hemodynamic Dysfunction Using Sonographic Technology in Rats

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is estimated to contribute to 19- 25% of all clinical cases of acute kidney injury (AKI) in critically ill patients. AKI detection has historically relied on metrics such as serum creatinine (sCr) or blood urea nitrogen (BUN) which are demonstrably inadequate in full assessment of nephrotoxicity in the early phase of renal dysfunction. Currently, there is no robust diagnostic method to accurately detect hemodynamic alteration in the early phase of AKI while such alterations might actually precede the rise in serum biomarker levels. Such early detection can help clinicians make an accurate diagnosis and help in in decision making for therapeutic strategy. Rats were treated with Cisplatin to induce AKI. Nephrotoxicity was assessed for six days using high-frequency sonography, sCr measurement and upon histopathology of kidney. Hemodynamic evaluation using 2D and Color-Doppler images were used to serially study nephrotoxicity in rats, using the sonography. Our data showed successful drug-induced kidney injury in adult rats by histological examination. Color-Doppler based sonographic assessment of AKI indicated that resistive-index (RI) and pulsatile-index (PI) were increased in the treatment group; and peak-systolic velocity (mm/s), end-diastolic velocity (mm/s) and velocity-time integral (VTI, mm) were decreased in renal arteries in the same group. Importantly, these hemodynamic changes evaluated by sonography preceded the rise of sCr levels. Sonography-based indices such as RI or PI can thus be useful predictive markers of declining renal function in rodents. From our sonography-based observations in the kidneys of rats that underwent AKI, we showed that these noninvasive hemodynamic measurements may consider as an accurate, sensitive and robust method in detecting early stage kidney dysfunction. This study also underscores the importance of ethical issues associated with animal use in research.

Early stage hemodynamic dysfunction is critical to the development of kidney disease. Yet, detection methodologies are limited. Recent advances in sonography provide a noninvasive, accurate option for early detection of kidney injury. This study outlines a step-by-step, sonographic methodology for detecting kidney dysfunction using a drug-induced nephrotoxicity rat model.

Détection précoce du médicament-Induced rénale hémodynamique Dysfonction Utilisation de échographique Technology chez le rat

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is ...

Cardiac Magnetic Resonance for the Evaluation of Suspected Cardiac Thrombus: Conventional and Emerging Techniques

We present the conventional cardiac magnetic resonance (CMR) protocol for evaluating a suspected thrombus and highlight emerging techniques.&#160;The appearance of a mass on certain magnetic resonance (MR) sequences can help differentiate a thrombus from competing diagnoses such as a tumor. T1 and T2 signal characteristics of a thrombus are related to the evolution of hemoglobin properties. A thrombus typically does not enhance following contrast administration, which also helps differentiation from a tumor. We also highlight the emerging role of T1 mapping in the evaluation of a thrombus, which can add another level of support in diagnosis. Prior to any CMR exam, patient screening and interviews are critical to ensure safety and to optimize patient comfort. Effective communication during the exam between the technologist and the patient promotes proper breath holding technique and higher quality images. Volumetric post processing and structured reporting are helpful to ensure that the radiologist answers the ordering services&#39; question and communicates these results effectively. Optimal pre-MR safety evaluation, CMR exam execution, and post exam processing and reporting allow for delivery of high quality radiological service in the evaluation of a suspected cardiac thrombus.

The goal of this article is to describe how cardiac magnetic resonance can be used for the evaluation and diagnosis of a suspected cardiac thrombus. The method presented will describe data acquisition as well as the pre-procedure and post-procedure protocol.

Résonance magnétique cardiaque pour l'évaluation du thrombus cardiaque présumé : techniques conventionnelles et émergentes

We present the conventional cardiac magnetic resonance (CMR) protocol for evaluating a suspected thrombus and highlight emerging techniques.&#160;The ...

Echocardiographic Assessment of Cardiac Anatomy and Function in Adult Rats

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional imaging to study the cardiac anatomy of the left ventricle and M-mode echo to assess its dimensions. However, this could limit a comprehensive study. Herein, we describe a protocol that allows an assessment of the heart chamber size, left ventricular function (systolic and diastolic) and valvular function. A conventional medical ultrasound machine was used in this protocol and different echo views were obtained through left parasternal, apical and suprasternal windows. In the left parasternal window, the long and short axis were acquired to analyze left chamber dimensions, right ventricle and pulmonary artery dimensions, and mitral, pulmonary and aortic valve function. The apical window allows the measurement of heart chamber dimensions and evaluation of systolic and diastolic parameters. It also allows Doppler assessment with detection and quantification of heart valve disturbances (regurgitation or stenosis). Different segments and walls of the left ventricle are visualized throughout all views. Finally, the ascending aorta, aortic arch, and descending aorta can be imaged through the suprasternal window. A combination of ultrasound imaging, Doppler flow and tissue Doppler assessment have been obtained to study cardiac morphology and function. This represents an important contribution to improve the assessment of cardiac function in adult rats with impact for research using these animal models.

A non-invasive protocol for transthoracic echocardiography assessment of cardiac anatomy and function for adult rats is presented in the current study. The heart valves, all four cardiac chambers and the ascending aorta, aortic arch and descending aorta are studied in detail.

Évaluation échocardiographique de l'anatomie cardiaque et de la fonction chez les rats adultes

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily and highly reproducible MI induction procedure is required to obtain further insight and better understanding of the underlying pathological changes. This procedure can also be used to evaluate the effects or potency of new and promising treatments (as drugs or interventions) in acute MI, subsequent remodeling and heart failure (HF). After intubation and pre-operative preparation of the animal, an anesthetic protocol with isoflurane was performed, and the surgical procedure was conducted&#160;quickly. Using a minimally invasive approach, the left anterior descending artery (LAD) was located and occluded by a ligature. The occlusion can be performed acutely for subsequent reperfusion (ischemia/reperfusion injury). Alternatively, the vessel can be ligated permanently to investigate the development of chronic MI, remodeling or HF. Despite common pitfalls, the drop-out rates are minimal. Various treatments such as remote ischemic conditioning can be examined for their cardioprotective potential pre-, peri- and post-operatively. The post-operative recovery was quick as the anesthesia was precisely controlled and the duration of the operation was short. Post-operative analgesia was administered for three days. The minimally invasive procedure reduces the risk of infection and inflammation. Furthermore, it facilitates rapid recovery. The &#8220;working heart&#8221; measurements were performed ex vivo and enabled precise control of preload, afterload and flow. This procedure requires specific equipment and training for adequate performance. This manuscript provides a detailed step-by-step introduction for conducting these measurements.

This article presents an efficient method to perform myocardial ischemia and subsequent chronic reperfusion in rats using a minimally invasive approach. In addition, left ventricular hemodynamic function of rats is assessed by echocardiography and isolated working heart methods.&#160;

Méthode invasive semi-minimale pour induire l’infarctus du myocarde chez les rats et l’évaluation de la fonction cardiaque par un système cardiaque de travail isolé

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...

Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ineffective in many patients. To improve patient care, novel and innovative therapeutic concepts causally targeting arrhythmia mechanisms are needed. To study the complex pathophysiology of arrhythmias, suitable animal models are necessary, and mice have been proven to be ideal model species to evaluate the genetic impact on arrhythmias, to investigate fundamental molecular and cellular mechanisms, and to identify potential therapeutic targets.
Implantable telemetry devices are among the most powerful tools available to study electrophysiology in mice, allowing continuous ECG recording over a period of several months in freely moving, awake mice. However, due to the huge number of data points (&gt;1 million QRS complexes per day), analysis of telemetry data remains challenging. This article describes a step-by-step approach to analyze ECGs and to detect arrhythmias in long-term telemetry recordings using the software, Ponemah, with its analysis modules, ECG Pro and Data Insights, developed by Data Sciences International (DSI). To analyze basic ECG parameters, such as heart rate, P wave duration, PR interval, QRS interval, or QT duration, an automated attribute analysis was performed using Ponemah to identify P, Q, and T waves within individually adjusted windows around detected R waves. 
Results were then manually reviewed, allowing adjustment of individual annotations. The output from the attribute-based analysis and the pattern recognition analysis was then used by the Data Insights module to detect arrhythmias. This module allows an automatic screening for individually defined arrhythmias within the recording, followed by a manual review of suspected arrhythmia episodes. The article briefly discusses challenges in recording and detecting ECG signals, suggests strategies to improve data quality, and provides representative recordings of arrhythmias detected in mice using the approach described above.

Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules.

Analyse des enregistrements électrocardiographiques à long terme pour détecter les arythmies chez la souris

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ...

Modified Heterotopic Abdominal Heart Transplantation and a Novel Aortic Regurgitation Model in Rats

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical technique. Modifying the transplantation procedure to strengthen the myocardial protection could prolong the ischemia time while preserving the donor&#39;s cardiac function. This technique&#39;s key points are as follows: transecting the donor&#39;s abdominal aorta before harvesting to unload the donor&#39;s heart; perfusing the donor&#39;s coronary arteries with a cold cardioplegic solution; and topical cooling of the donor&#39;s heart during the anastomosis procedure. Consequently, since this procedure prolongs the acceptable ischemia time, beginners can easily perform it and achieve a high success rate.
Moreover, a new aortic regurgitation (AR) model was established in this work using a technique different from the existing one,&#160;which is created by inserting a catheter from the right carotid artery and puncturing the native aortic valve under continuous echocardiographic guidance. A heterotopic abdominal heart transplantation was performed using the novel AR model. In the protocol, after the donor&#39;s heart is harvested, a stiff guidewire is inserted into the donor&#39;s brachiocephalic artery and advanced toward the aortic root. The aortic valve is punctured by pushing the guidewire further even after the resistance is felt, thus inducing AR. It is easier to damage the aortic valve using this method than with the procedure described in the conventional AR model. Additionally, this novel AR model does not contribute to the recipient&#39;s circulation; therefore, this method is expected to produce a more severe AR model than the conventional procedure.

This study demonstrates a reproducible heterotopic abdominal heart transplantation technique in rats that beginners can learn and perform. Additionally, a novel aortic regurgitation model in rats is generated by performing heterotopic abdominal heart transplantation and damaging the donor's aortic valve using a guidewire after harvesting.

Transplantation cardiaque abdominale hétérotopique modifiée et nouveau modèle de régurgitation aortique chez le rat

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical ...

Manipulation standardisée du Tuina pour l’arthrose du genou chez le rat

Tuina Manipulation to Reduce Inflammation and Cartilage Loss in Knee Osteoarthritis Rats

Clinical trials suggest that Tuina manipulation is effective in treating knee osteoarthritis (KOA), while further studies are required to discover its mechanism. Therefore, the manipulation of animal models of knee osteoarthritis is critical. This protocol provides a standard process for Tuina manipulation on KOA rats and a preliminary exploration of the mechanism of Tuina for KOA. The press and kneading manipulation method (a kind of Tuina manipulation that refers to pressing and kneading the specific area of the body surface) is applied on 5 acupoints around the knee joint of rats. The force and frequency of the manipulation were standardized by finger pressure recordings, and the position of the rat during manipulation is described in detail in the protocol. The effect of manipulation can be measured by pain behavior tests and microscopic findings in synovial and cartilage. KOA rats showed significant improvement in pain behavior. The synovial tissue inflammatory infiltration was reduced in the Tuina group, and the expression of tumor necrosis factor (TNF)-&#945; was significantly lower. Compared to the control group, chondrocyte apoptosis was less in the Tuina group. This study provides a standardized protocol for Tuina manipulation on KOA rats and preliminary proof that the therapeutic effects of Tuina may be related to reducing synovial inflammation and delayed chondrocyte apoptosis.

Pleins feux sur l’auteur : Comprendre le mécanisme de manipulation du tuina chez le rat 

We present a protocol for Tuina manipulation performed on plaster-immobilized-induced knee osteoarthritis rats. Based on the preliminary results, it suggested that the efficacy of the method relied on the reduction of inflammation and cartilage loss.

Manipulation du tuina pour réduire l’inflammation et la perte de cartilage chez les rats souffrant d’arthrose du genou

Clinical trials suggest that Tuina manipulation is effective in treating knee osteoarthritis (KOA), while further studies are required to discover its ...