Questa ricerca è stata sostenuta da una sovvenzione dal Uniti Cittadini per la ricerca in Epilessia (CURE) per SLB.

<p class="jove_title"&gt; 1. Materiali da Costruzione</p&gt;<ol&gt;<li&gt; Un catetere giugulare è costruito da un pezzo (100 mm) di tubo in polietilene PE-50, smussati da un lato, e poi riempito con soluzione salina eparina (50 U eparina / mL di soluzione salina).</li&gt;<li&gt; Gli elettrodi di registrazione ECG sono costruiti da due da 100 mm di lunghezza del filo d&#39;argento isolato (30AWG). Una estremità dei fili è spogliato e saldato ad un microconnettore, e l&#39;isolamento è attorcigliato per formare un terzo filo che viene utilizzato come terreno. Cinque mm di isolamento è spogliato dalla fine distale dei fili e scartato.</li&gt;</ol&gt;<p class="jove_title"&gt; 2. L&#39;impianto di catetere giugulare Vena</p&gt;<ol&gt;<li&gt; Anestetizzare l&#39;animale con la somministrazione di uretano, ip (1,2 g / kg).</li&gt;<li&gt; Controllate regolarmente (intervalli di 10 min), profondità dell&#39;anestesia, valutando la risposta del pedale ritiro e / o riflessi oculari. Se necessario, supplemento anestesia.</li&gt;<li&gt; Dopo l&#39;animale si trova al piano adeguato di anestesia, radere la parte destra del collo dalla clavicola al mento.</li&gt;<li&gt; Fare un incisione longitudinale (10-15 mm) nella pelle sopra l&#39;arteria carotide e aprire l&#39;incisione.</li&gt;<li&gt; Utilizzo di tecniche di dissezione smussa, si sviluppa il muscolo sottostante per individuare e isolare la vena giugulare destra.</li&gt;<li&gt; Mettere due pezzi di seta chirurgica (# 2) sotto la vena giugulare e posizionare i punti di sutura al porzioni più rostrale e caudale dell&#39;incisione. Legare la legatura rostrale di interrompere il flusso attraverso la vena.</li&gt;<li&gt; Ritrarre la legatura caudale di sollevare la nave fuori dal tessuto sottostante e fare un piccolo taglio. Poi, inserire l&#39;estremità smussato della eparina pieno (50 U / ml soluzione fisiologica) catetere in polietilene PE-50 (100 mm di lunghezza), e far progredire la punta circa 8 mm al livello dell&#39;atrio destro.</li&gt;<li&gt; Al fine di assicurare il catetere, cravatta la legatura caudale sia intorno alla nave e catetere. Infine, chiudere la ferita con due clip ferita o sutura.</li&gt;<li&gt; Durante l&#39;impianto del catetere, l&#39;estremità esposta può essere bloccato con un hemostat o collegato per evitare il riflusso di sangue prima di attaccamento a una pompa per infusione.</li&gt;</ol&gt;<p class="jove_title"&gt; 3. L&#39;impianto di elettrodi CG</p&gt;<ol&gt;<li&gt; Mettere l&#39;animale sul dorso e radere al petto.</li&gt;<li&gt; Per il posizionamento degli elettrodi, fare due incisioni longitudinali (≈ 10 mm), uno in alto a destra e uno nei quadranti in basso a sinistra del petto, e libera la cute sovrastante per esporre i muscoli del torace.</li&gt;<li&gt; Sutura una delle esposizione di 5 mm punte dei fili d&#39;argento elettrodi nei muscoli del torace in ciascuna delle zone esposte, e posizionare l&#39;elettrodo di massa per via sottocutanea.</li&gt;<li&gt; Chiudere le incisioni con clip ferita e collegare il microconnettore nel dispositivo di registrazione.</li&gt;<li&gt; Avvolgere l&#39;animale liberamente in un asciugamano per mantenere la temperatura corporea durante la procedura.</li&gt;</ol&gt;<p class="jove_title"&gt; 4. Registrazione ECG</p&gt;<ol&gt;<liLe registrazioni&gt; sono realizzati con un Powerlab sistema di acquisizione dati e computer Macintosh o hardware simile / software (amplificata, 50X, filtrata, 1-1000 Hz).</li&gt;<li&gt; Dopo un periodo di equilibrio di 20-30 minuti, registrare ECG per 20 minuti.</li&gt;</ol&gt;<p class="jove_title"&gt; 5. Indurre aritmie ventricolari</p&gt;<ol&gt;<li&gt; Fissare il catetere giugulare vena di una siringa remoto collocato in una pompa per infusione programmabile.</li&gt;<li&gt; Iniziare l&#39;infusione aconitina ad un tasso di consegnare una dose costante di 5 ug / kg / min per 7 minuti.</li&gt;<liFibrillazione ventricolare&gt; seguito o la fine del periodo di infusione, l&#39;eutanasia dell&#39;animale utilizzando una procedura approvata.</li&gt;</ol&gt;<p class="jove_title"&gt; 6. Analisi di ECG</p&gt;<ol&gt;<li&gt; L&#39;intervallo QT rappresenta la durata totale di attività elettrica ventricolare. Fig. 1 mostra una registrazione ECG modello e la durata dell&#39;intervallo QT. Calcolare il tempo medio tra l&#39;inizio del Q-wave e cessazione del T-wave per tutti i battiti cardiaci registrati negli ultimi cinque minuti di intervallo ottenuti durante il periodo di 20 minuti di registrazione.</li&gt;<li&gt; Per correggere l&#39;intervallo QT per le differenze nella frequenza cardiaca (QTc), usare la formula Bazett, il QTc = QT / (RR)<sup&gt; ½</sup&gt;, Dove RR è l&#39;intervallo medio tra battiti cardiaci. L&#39;intervallo RR è calcolato come la durata tra successive onde Q ottenuti durante il periodo analizzato.</li&gt;<li&gt; La dispersione QT (QTd) è calcolato sottraendo il QT minima dal QT massimo registrato per ciascun animale.</li&gt;</ol&gt;<p class="jove_title"&gt; 7. Analisi di variabilità della frequenza cardiaca</p&gt;<ol<li&gt; I software (cioè LabChart 7, ADInstruments, Inc.) che analizzano la variabilità negli intervalli RR ottenuti durante il periodo di analisi vengono utilizzati per il calcolo automatico della varianza sia temporale e / o spettrale della frequenza cardiaca.</li</ol&gt;<p class="jove_title"&gt; 8. Analisi di suscettibilità ad aritmie ventricolari</p&gt;<ol<li&gt; Calcolare la latenza tra l&#39;inizio dell&#39;infusione aconitina alla prima contrazione ventricolare prematura (PVC, fig. 2, Pannello 1), tachicardia ventricolare (VT, Fig, 2, Panel 2) e la fibrillazione ventricolare (VF, Fig. 2. Panel 3 ).</li</ol&gt;<p class="jove_title"&gt; 9. Rappresentante Risultati</p&gt;<p class="jove_content"&gt; Fig. 3 illustra una misura di HRV nel dominio spettrale (radice quadratico medio della deviazione standard degli intervalli RR, RMSSD) nei ratti di controllo e negli animali sottoposti a SE una settimana prima del test. Questa misura di HRV, che rappresenta i cambiamenti nel controllo parasimpatico della funzione cardiaca<sup&gt; 26</sup&gt;, È significativamente diminuito negli animali seguente stato di male epilettico. Fig. 4 mostra che entrambi intervallo QT corretto (QTc, Panel A) e la dispersione QT (QTd, pannello B) sono aumentati in modo significativo due settimane dopo SE<sup&gt; 27</sup&gt;. Presi insieme, questi dati prevedono che SE aumenta il rischio di aritmie ventricolari. Questa previsione è confermata dai risultati che i periodi di infusione aconitina necessaria per indurre le aritmie sperimentale (PVC, VT, VF) osservati in questi studi sono stati significativamente più piccoli in animali a seguito 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; Figura 1.</strong&gt; Modello di registrazione ECG di un battito cardiaco normale che mostra P, QRS, e le onde T. L&#39;intervallo QT è calcolato come il tempo tra le linee tratteggiate.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig2.jpg" alt="figure 2" /<br /<strong&gt; Figura 2. Pannello 1)</strongContrazioni ventricolari&gt; precoce (PVC) sono isolati contrazioni dei ventricoli (B) che si verificano tra i battiti cardiaci normali (A). Registrazioni in PVC sono caratterizzati dalla assenza di onde P e T.<strong&gt; Panel 2</strongVentricolare&gt; tachicardia (VT) è una serie di contrazioni ventricolari multiple (C) che si verificano senza battiti cardiaci intervenire normale (A).<strong&gt; Pannello di 3</strongVentricolare&gt; fibrillazione ventricolare (VF) è la mancanza di ritmo e distinguibile alcuna associazione tra QRS e onde P (D).</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig3.jpg" alt="figure 3" /<br /<strong&gt; Figura 3.</strong&gt; La radice quadratico medio della deviazione standard (RMSSD; msec) degli intervalli tra i battiti cardiaci osservato nei ratti di controllo e negli animali sottoposti a stato di male epilettico (SE) 1 settimana prima del test. ** P &lt;0,01 rispetto al controllo.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig4.jpg" alt="figure 4" /<br /<strong&gt; Figura 4.</strong&gt; Medio dell&#39;intervallo QT corretto (Pannello A) e la dispersione QT (Pannello B) calcolato da registrazioni ECG ottenuti da animali di controllo (Cont) e di ratti sottoposti a stato di male epilettico (SE) due settimane prima del test. * P &lt;0,05 rispetto al Cont. (Metcalf et al., Am. J. Physiol. Cuore e Circ, 2009, Am Soc Physiol, utilizzato con il permesso di<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; Figura 5.</strong&gt; Latenze (sec) tra l&#39;inizio di infusione aconitina e il 1 ° contrazione ventricolare prematura (PVC), tachicardia ventricolare (VT), e la fibrillazione ventricolare (FV) negli animali di controllo (Cont) e nei ratti sottoposti a stato di male epilettico (SE) due settimane prima ai test. * P &lt;0,05, ** p &lt;0,01 rispetto al Cont. (Metcalf et al., Am. J. Physiol. Cuore e Circ, 2009, Am Soc Physiol, utilizzato con il permesso di<sup&gt; 27</sup&gt;).</p&gt;

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Due aspetti delle procedure descritte sono di importanza critica. In primo luogo, la velocità di somministrazione aconitina al cuore devono essere equivalenti tra gli animali. Ciò richiede il posizionamento coerente delle punte catetere venoso giugulare rispetto al cuore, e la regolazione accurata delle velocità di infusione. Il tasso di consegna aconitina al cuore deve essere uguale per valutare adeguatamente l&#39;insorgenza di aritmie ventricolari rispetto alla suscettibilità alterata. Se la consegna aconitina va...

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

Aritmie cardiache letali contribuiscono alla mortalità in una serie di condizioni patologiche. Diversi parametri ottenuti da un non-invasiva, elettrocardiogramma facilmente ottenibile (ECG) sono stabilite, ben validati indicatori prognostici di rischio cardiaco in pazienti affetti da una serie di cardiomiopatie. Aumento della frequenza cardiaca, diminuzione della variabilità della frequenza cardiaca (HRV), e una maggiore durata e la variabilità di attività elettrica cardiaca ventricolare (intervallo QT) sono indicativi di aumentato rischio cardiaco 1-4. Nei modelli animali, è importante confrontare questi ECG derivati ​​variabili e predisposizione alle aritmie indotte sperimentalmente. L&#39;infusione endovenosa del aconitina agente aritmogena è stato ampiamente utilizzato per valutare la suscettibilità alle aritmie in una serie di condizioni sperimentali, tra cui modelli animali di depressione 5 e ipertensione 6, a seguito dell&#39;esercizio 7 e l&#39;esposizione agli inquinanti atmosferici 8, così come la determinazione del antiaritmici l&#39;efficacia di agenti farmacologici 9,10. Va notato che la dispersione QT negli esseri umani è una misura della variazione dell&#39;intervallo QT in tutto il set completo di porta da uno standard di ECG a 12 derivazioni. Di conseguenza, la misura della dispersione QT dal 2-ECG nel ratto descritti in questo protocollo è diverso da quello calcolato da uomo registrazioni ECG. Questo rappresenta un limite nella traduzione dei dati ottenuti dai roditori umano medicina clinica. Stato di male epilettico (SE) è un attacco singolo o una serie di continuo crisi ricorrenti di durata superiore a 30 min 11,12 11,12, ed i risultati della mortalità nel 20% dei casi 13. Molti individui sopravvivere alla SE, ma muoiono entro 30 giorni 14,15. Il meccanismo di (s) di questo mortalità ritardo non è del tutto chiaro. È stato suggerito che le aritmie ventricolari letali contribuire a molte di queste morti 14-17. Oltre a SE, pazienti con crisi epilettiche spontaneamente ricorrenti, epilessia cioè, sono a rischio di morte prematura improvvisa e inattesa associata a epilessia (SUDEP) 18. Come per SE, i precisi meccanismi che mediano SUDEP non sono noti. E &#39;stato proposto che le anomalie e le aritmie ventricolari risultante dare un contributo significativo 18-22. Per studiare i meccanismi di crisi legate alla morte cardiaca, e l&#39;efficacia delle terapie cardioprotettivi, è necessario ottenere entrambi gli indicatori ECG derivati ​​di rischio e valutare suscettibilità alle aritmie cardiache in modelli animali di disturbi convulsivi 23-25. Qui si descrivono i metodi per l&#39;impianto di elettrodi ECG nella Sprague-Dawley di laboratorio ratto (Rattus norvegicus), a seguito di SE, raccolta e analisi di registrazioni ECG, e induzione di aritmie durante l&#39;infusione endovenosa di aconitina. Queste procedure possono essere utilizzati per determinare direttamente i rapporti tra ECG derivate misure di attività elettrica cardiaca e suscettibilità alle aritmie ventricolari nei modelli di ratto di disturbi convulsivi o qualsiasi patologia associata ad un aumentato rischio di morte cardiaca improvvisa.

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

Tecniche per la misurazione dell&#39;attività elettrica del cuore con elettrocardiogramma (ECG), e l&#39;analisi dei fattori di rischio cardiaci e predisposizione alle aritmie seguenti stato epilettico (SE) nel ratto sono descritti.

Metodi per la valutazione ECG degli indicatori di rischio cardiaco, e suscettibilità a Aconitina indotte aritmie nei ratti dopo stato epilettico

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 Views.  University of Utah. Tecniche per la misurazione dell'attività elettrica del cuore con elettrocardiogramma (ECG), e l'analisi dei fattori di rischio cardiaci e predisposizione alle aritmie seguenti stato epilettico (SE) nel ratto sono descritti.

Video: 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.

Crescente aortica Costrizione in ratti per la creazione di sovraccarico di pressione cardiaca Ipertrofia Modello

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

Ricerca

Medicina

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.

La diagnosi precoce del farmaco-indotta renale emodinamica erettile Utilizzando ecografica Technology di ratti

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.

Risonanza magnetica cardiaca per la valutazione di un trombo cardiaco sospetto: tecniche convenzionali ed emergenti

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.

Valutazione ecocardiografica dell'anatomia e della funzione cardiaca nei ratti adulti

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;

Metodo semi-minimo invasivo per indurre l'infarto miocardico nei ratti e la valutazione della funzione cardiaca da parte di un sistema cardiaco funzionante isolato

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.

Analisi delle registrazioni elettrocardiografiche a lungo termine per rilevare le aritmie nei topi

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.

Trapianto di cuore addominale eterotopico modificato e un nuovo modello di rigurgito aortico nei ratti

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

Manipolazione standardizzata di Tuina per l'artrosi del ginocchio nei ratti

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.

Autore in primo piano: Comprendere il meccanismo della manipolazione del tuina nei ratti 

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.

Manipolazione del tuina per ridurre l'infiammazione e la perdita di cartilagine nei ratti affetti da osteoartrite del ginocchio

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