Esta investigación fue financiada por una beca de las Naciones Unidas para la Investigación de los ciudadanos en la Epilepsia (CURE) de SLB.

<p class="jove_title"&gt; 1. Materiales para construir</p&gt;<ol&gt;<li&gt; Un catéter de la vena yugular se construye a partir de una pieza (100 mm) de tubería de polietileno PE-50, biselada en un extremo, y se rellena con solución salina con heparina (50 U de heparina / ml de solución salina).</li&gt;<li&gt; Los electrodos de ECG se construyen a partir de dos longitudes de 100 mm de alambre de plata aislado (30AWG). Uno de los extremos de ambos cables se elimina y se sueldan a una microconnector, y el aislamiento se tuerce para formar un tercer cable que se utiliza como base. Cinco milímetros de aislamiento se extrae del extremo distal de los cables y se desecha.</li&gt;</ol&gt;<p class="jove_title"&gt; 2. La implantación de catéter de la vena yugular</p&gt;<ol&gt;<li&gt; Se anestesia al animal mediante la administración de uretano, ip (1,2 g / kg).</li&gt;<li&gt; Comprobar con regularidad (intervalos de 10 minutos) la profundidad de la anestesia mediante la evaluación de la respuesta de retirada del pedal y / o reflejos oculares. Si es necesario, complementar la anestesia.</li&gt;<li&gt; Después de que el animal está en el plano adecuado de anestesia, se afeitan el lado derecho del cuello de la clavícula hasta el mentón.</li&gt;<li&gt; Haga una incisión longitudinal (10-15 mm) en la piel sobre la arteria carótida y abrir la incisión.</li&gt;<li&gt; Utilización de técnicas de disección roma, se extendió el músculo subyacente para localizar y aislar la vena yugular derecha.</li&gt;<li&gt; Coloque dos piezas de seda quirúrgica (# 2) en la vena yugular, y la posición de los puntos de sutura en las partes más rostral y caudal de la incisión. Lazo de la ligadura de interrumpir el flujo de rostral a través de la vena.</li&gt;<li&gt; Retirar la ligadura caudal para levantar el vaso de los tejidos subyacentes y hacer un pequeño corte. A continuación, inserte el extremo biselado de la heparina en aceite (50 U / ml de solución salina) catéter de polietileno PE-50 (100 mm de longitud), y avanzar en la punta de unos 8 mm para el nivel de la aurícula derecha.</li&gt;<li&gt; Con el fin de asegurar el catéter, la corbata de la ligadura caudal alrededor de los dos el buque y el catéter. Finalmente, cierra la herida con una herida o clips de sutura.</li&gt;<li&gt; Durante la implantación del catéter, el extremo opuesto está bien sujeta con una pinza hemostática o tapado para evitar el reflujo de sangre antes de la adhesión a una bomba de infusión.</li&gt;</ol&gt;<p class="jove_title"&gt; 3. La implantación de electrodos CG</p&gt;<ol&gt;<li&gt; Colocar el animal sobre su espalda y afeitar el pecho.</li&gt;<li&gt; Para la colocación de los electrodos, hacer dos incisiones longitudinales (≈ 10 mm), una en la parte superior derecha y uno en los cuadrantes inferiores izquierdo del pecho, y sin la piel que recubre para exponer los músculos del tórax.</li&gt;<li&gt; Sutura uno de los expuestos de 5 mm puntas de los electrodos de alambre de plata en los músculos del tórax en cada una de las zonas expuestas, y colocar el electrodo de tierra por vía subcutánea.</li&gt;<li&gt; Cierre de las incisiones con grapas de la herida y conecte el microconnector en el dispositivo de grabación.</li&gt;<li&gt; Ajuste el animal suelto en una toalla para mantener la temperatura corporal durante el procedimiento.</li&gt;</ol&gt;<p class="jove_title"&gt; 4. Registro del ECG</p&gt;<ol&gt;<liGrabaciones&gt; se realizan mediante un sistema de adquisición de datos Powerlab y el ordenador Macintosh o equipos similares / software (amplificada, 50X, filtrada, 1000-1000 Hz).</li&gt;<li&gt; Después de un período de 20-30 minutos de equilibrio, registro ECG durante 20 minutos.</li&gt;</ol&gt;<p class="jove_title"&gt; 5. La inducción de arritmias ventriculares</p&gt;<ol&gt;<li&gt; Conecte el catéter de la vena yugular con una jeringa remoto colocado en una bomba de infusión programable.</li&gt;<li&gt; Iniciar la infusión de aconitina, a una tasa de administrar una dosis constante de 5 ug / kg / min durante 7 minutos.</li&gt;<liLa fibrilación&gt; ventricular Después o al final del periodo de perfusión, la eutanasia de los animales mediante un procedimiento aprobado.</li&gt;</ol&gt;<p class="jove_title"&gt; 6. El análisis de ECG</p&gt;<ol&gt;<li&gt; El intervalo QT representa la duración total de la actividad eléctrica ventricular. Fig. 1 muestra un modelo de registro de ECG y la duración del intervalo QT. Calcular el tiempo medio entre el inicio de la onda Q y la terminación de la onda T para todos los latidos del corazón registrados en un intervalo de cinco minutos obtenida durante el período de 20 minutos de grabación.</li&gt;<li&gt; Para corregir el intervalo QT por las diferencias en la frecuencia cardíaca (QTc), utilice la fórmula de Bazett, QTc = QT / (RR)<sup&gt; ½</sup&gt;, Donde RR es el intervalo entre los latidos del corazón. El intervalo RR se calcula como la duración entre sucesivas ondas Q obtenidos durante el período analizado.</li&gt;<li&gt; La dispersión del QT (QTd) se calcula restando el QT mínimo del intervalo QT máximo registrado para cada animal.</li&gt;</ol&gt;<p class="jove_title"&gt; 7. Análisis de la variabilidad del ritmo cardíaco</p&gt;<ol<li&gt; Los programas de software (es decir, LabChart 7, ADInstruments, Inc.) que analizan la variabilidad de los intervalos RR obtenidos durante el período de análisis se utilizan para el cálculo automático de variación temporal y / o espectral de la frecuencia cardíaca.</li</ol&gt;<p class="jove_title"&gt; 8. Análisis de la susceptibilidad a las arritmias ventriculares</p&gt;<ol<li&gt; Calcular la latencia del inicio de la infusión de aconitina a la contracción ventricular prematura primero (PVC, fig. 2, Grupo 1), taquicardia ventricular (VT, Fig. 2, Grupo 2) y la fibrilación ventricular (FV, la figura 2. Panel 3 ).</li</ol&gt;<p class="jove_title"&gt; 9. Resultados representante</p&gt;<p class="jove_content"&gt; La figura. 3 ilustra una de las medidas de la VFC en el dominio espectral (Root Mean cuadrado de la desviación estándar del intervalo RR, RMSSD) en ratas control y en los animales que se sometieron a SE una semana antes de la prueba. Esta medida de la VFC, que representa los cambios en el control parasimpático de la función cardíaca<sup&gt; 26</sup&gt;, Es significativamente menor en los animales después de un estado epiléptico. Fig. 4 muestra que tanto el intervalo QT corregido (QTc, Grupo A) y la dispersión del intervalo QT (QTd, Grupo B) se incrementó significativamente dos semanas después de SE<sup&gt; 27</sup&gt;. En conjunto, estos datos predicen que la SE aumenta el riesgo de arritmias ventriculares. Esta predicción se confirma por el hallazgo de que los periodos de infusión de aconitina necesaria para inducir las arritmias experimental (PVC, TV, FV) observados en estos estudios fueron significativamente menores en los animales después de 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; Modelo de Registro de ECG de un latido del corazón normal con P, QRS y ondas T. El intervalo QT se calcula como el tiempo entre las líneas de puntos.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig2.jpg" alt="figure 2" /<br /<strong&gt; Figura 2. Grupo 1)</strongContracciones&gt; ventriculares prematuras (CVP) se aíslan las contracciones de los ventrículos (B) que se producen entre los latidos cardíacos normales (A). Grabaciones de PVC se caracteriza por la ausencia de ondas P y T.<strong&gt; Panel 2</strongTaquicardia&gt; ventricular (VT) es una serie de contracciones ventriculares múltiples (C) que se producen con los latidos del corazón no intervenir normal (A).<strong&gt; Panel 3</strongLa fibrilación&gt; ventricular (FV) es la falta de ritmo apreciable y no hay asociación entre QRS y ondas 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 media de la raíz cuadrada de la desviación estándar (RMSSD; ms) de los intervalos entre los latidos del corazón en ratas control y en los animales sometidos a estado de mal epiléptico (SE) 1 semana antes de la prueba. ** P &lt;0.01 en comparación con el control.</p&gt;<p class="jove_content"<img src="/files/ftp_upload/2726/2726fig4.jpg" alt="figure 4" /<br /<strong&gt; Figura 4.</strong&gt; La media de intervalo QT corregido (Grupo A) y la dispersión del intervalo QT (Grupo B) calculado a partir de registros de ECG obtenida de los animales de control (Cont.) y de ratas sometidas a estado de mal epiléptico (SE), dos semanas antes de la prueba. * P &lt;0,05 en comparación con cont. (Metcalf, et al., Am. J. Physiol. Corazón y Circ de 2009, Am Soc Physiol, usado con permiso 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; Figura 5.</strong&gt; Latencias (s) entre el inicio de la infusión de aconitina y la contracción primera ventricular prematura (CVP), taquicardia ventricular (TV) y fibrilación ventricular (FV) en los animales control (Cont.) y ratas sometidas a estado de mal epiléptico (SE) dos semanas antes de la prueba. * P &lt;0,05, ** p &lt;0,01 en comparación con cont. (Metcalf, et al., Am. J. Physiol. Corazón y Circ de 2009, Am Soc Physiol, usado con permiso de<sup&gt; 27</sup&gt;).</p&gt;

<ol>
	<li>Chugh, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determinants+of+prolonged+QT+interval+and+their+contribution+to+sudden+death+risk+in+coronary+artery+disease:+The+Oregon+sudden+unexpected+death+study.">Determinants of prolonged QT interval and their contribution to sudden death risk in coronary artery disease: The Oregon sudden unexpected death study.</a> Circulation. 119, 663-670 (2009).</li><li>Darbar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitivity+and+specificity+of+QTc+dispersion+for+identification+of+risk+of+cardiac+death+in+patients+with+peripheral+vascular+disease.">Sensitivity and specificity of QTc dispersion for identification of risk of cardiac death in patients with peripheral vascular disease.</a> BMJ. 312, 874-878 (1996).</li><li>Bruyne, M. C. d. e. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=QTc+dispersion+predicts+cardiac+mortality+in+the+elderly:+The+Rotterdam+study.">QTc dispersion predicts cardiac mortality in the elderly: The Rotterdam study.</a> Circulation. 97, 467-472 (1998).</li><li>Malik, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+rate+variability:+standards+of+measurement,+physiological+interpretation,+and+clinical+use.">Heart rate variability: standards of measurement, physiological interpretation, and clinical use.</a> Circulation. 93, 1043-1065 (1996).</li><li>Grippo, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+susceptibility+to+ventricular+arrhythmias+in+a+rodent+model+of+experimental+depression.">Increased susceptibility to ventricular arrhythmias in a rodent model of experimental depression.</a> Am. J. Physiol. 286, H619-H626 (2004).</li><li>Li, M., Wang, J., Xie, H. H., Shen, F. M., Su, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+susceptibility+of+ventricular+arrhythmia+to+aconitine+in+conscious+hypertensive+rats.">The susceptibility of ventricular arrhythmia to aconitine in conscious hypertensive rats.</a> Acta. 28, 211-215 (2007).</li><li>Beig, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voluntary+exercise+does+not+affect+stress-induced+tachycardia,+but+improves+resistance+to+cardiac+arrhythmias+in+rats.">Voluntary exercise does not affect stress-induced tachycardia, but improves resistance to cardiac arrhythmias in rats.</a> Clin. Exp. Pharm. Physiol. , (2010).</li><li>Hazari, M. S., Haykai-Coates, N., Winsett, D. W., Costa, D. L., Farraj, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+single+exposure+to+particulate+or+gaseous+ari+pollution+increases+the+risk+of+aconitine-induced+cardiac+arrhythmia+in+hypertensive+rats.">A single exposure to particulate or gaseous ari pollution increases the risk of aconitine-induced cardiac arrhythmia in hypertensive rats.</a> Toxicol. Sci. 112, 532-542 (2009).</li><li>Amran, M. S., Hashimoto, K., Homma, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+sodium-calcium+exchange+inhibitors,+KB-R7943+and+SEA0400,+on+aconitine-induced+arrhythmias+in+guinea+pigs+in+vivo,+in+vitro,+and+in+computer+simulation+studies.">Effects of sodium-calcium exchange inhibitors, KB-R7943 and SEA0400, on aconitine-induced arrhythmias in guinea pigs in vivo, in vitro, and in computer simulation studies.</a> J. Pharmacol. Exp. Ther. 310, 83-89 (2004).</li><li>Klekot, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antiarrhythmic+activity+of+a+membrane-protecting+agent+Sal'magin+in+rats+with+aconitine-induced+arrhythmias.">Antiarrhythmic activity of a membrane-protecting agent Sal'magin in rats with aconitine-induced arrhythmias.</a> Bull. Exp. Biol. Med. 142, 209-211 (2006).</li><li>Lowenstein, D. H., Alldredge, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Status+Epilepticus.">Status Epilepticus.</a> New England J. Med. 338, 970-976 (1998).</li><li>Walker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Status+epilepticus:+an+evidence+based+guide.">Status epilepticus: an evidence based guide.</a> BMJ. 331, 673-677 (2005).</li><li>Shorvon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Status epilepticus: its clinical features and treatment in children and adults. , (1994).</li><li>Boggs, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamic+monitoring+prior+to+and+at+the+time+of+death+in+status+epilepticus.">Hemodynamic monitoring prior to and at the time of death in status epilepticus.</a> Epilepsy Res. 31, 199-209 (1998).</li><li>Walton, N. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systemic+effects+of+generalized+convulsive+status+epilepticus.">Systemic effects of generalized convulsive status epilepticus.</a> Epilepsia. 34, S54-S58 (1993).</li><li>Boggs, J. G., Painter, J. A., DeLorenzo, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+electrocardiographic+changes+in+status+epilepticus.">Analysis of electrocardiographic changes in status epilepticus.</a> Epilepsy Res. 14, 87-94 (1993).</li><li>Painter, J. A., Shiel, F. O., DeLorenzo, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+pathology+findings+in+status+epilepticus.">Cardiac pathology findings in status epilepticus.</a> Epilepsia. 34, 30-30 (1993).</li><li>Lathers, C. M., Schraeder, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+pharmacology:+drugs+as+a+benefit+and/or+risk+in+sudden+unexpected+death+in+epilepsy.">Clinical pharmacology: drugs as a benefit and/or risk in sudden unexpected death in epilepsy.</a> J. Clin. Pharmacol. 42, 123-126 (2002).</li><li>Dashieff, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sudden+unexpected+death+in+epilepsy:+a+series+from+an+epilepsy+surgery+program+and+specualtion+of+the+relationship+to+sudden+cardiac+death.">Sudden unexpected death in epilepsy: a series from an epilepsy surgery program and specualtion of the relationship to sudden cardiac death.</a> J. Clin. Neurophysiol. 8, 216-222 (1991).</li><li>Tigaran, P. -. C. o. d. r. e. a., Dalager-Pedersen, S., Baandrup, S., Dam, U., M, ., Vesterby-Charles, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sudden+unexpected+death+in+epilepsy:+is+death+by+seizures+a+cardiac+event.">Sudden unexpected death in epilepsy: is death by seizures a cardiac event.</a> Am. J. Forensic Med. Pathol. 26, 99-105 (2005).</li><li>Leung, H., Kwan, P., Elger, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Finding+the+missing+link+between+ictal+bradyarrhythmia,+ictal+asystole,+and+sudden+unexpected+death+in+epilepsy.">Finding the missing link between ictal bradyarrhythmia, ictal asystole, and sudden unexpected death in epilepsy.</a> Epilepsy and Behavior. 9, 19-30 (2006).</li><li>Nei, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EEG+and+ECG+in+sudden+unexplained+death+in+epilepsy.">EEG and ECG in sudden unexplained death in epilepsy.</a> Epilepsia. 45, 338-345 (2004).</li><li>Dudek, F. E., Clark, S., Williams, P. A., Grabenstatter, H. L., Pitkanen, A., Schwartzkroin, P. A., Moshe, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Models of Seizures and Epilepsy. , 415-432 (2006).</li><li>Turski, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limbic+seizures+produced+by+pilocarpine+in+rats:+behavioral+electroencephalographic,+and+neuropathological+study.">Limbic seizures produced by pilocarpine in rats: behavioral electroencephalographic, and neuropathological study.</a> Behav. Brain Res. 9, 315-335 (1989).</li><li>Kulkarni, S. K., George, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lithium-pilocarpine+neurotoxicity:+a+potential+model+of+status+epilepticus.">Lithium-pilocarpine neurotoxicity: a potential model of status epilepticus.</a> Methods Find. Exp. Clin. Pharamacol. 17, 551-567 (1995).</li><li>Stein, P. K., Bosner, M. S., Kleiger, R. E., Conger, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hart+rate+variability:+a+measure+of+cardiac+autonomic+tone.">Hart rate variability: a measure of cardiac autonomic tone.</a> Am. Heart J. 127, 1376-1381 (1994).</li><li>Metcalf, C. S., Poelzing, S., Little, J. G., Bealer, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Status+epilepticus+induces+cardiac+myofilament+damage+and+increased+susceptibility+to+arrhythmias+in+rat.">Status epilepticus induces cardiac myofilament damage and increased susceptibility to arrhythmias in rat.</a> Am. J. Physiol. 297, H2120-H2127 (2009).</li></ol>

Dos aspectos de los procedimientos descritos son de importancia crítica. En primer lugar, la velocidad de administración de aconitina para el corazón debe ser equivalente a través de los animales. Esto requiere la colocación consistente de las puntas de catéter de vena yugular en relación con el corazón, y un cuidadoso ajuste de la velocidad de infusión. La tasa de partos aconitina a los corazones deben ser iguales a fin de evaluar adecuadamente la aparición de arritmias ventriculares en relación con la susce...

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

Arritmias cardíacas mortales contribuyen a la mortalidad en una serie de condiciones patológicas. Varios parámetros obtenidos de una manera no invasiva, electrocardiograma de fácil acceso (ECG) se han establecido, bien validados indicadores de pronóstico de riesgo cardíaco en pacientes que sufren de una serie de cardiopatías. Aumento del ritmo cardíaco, disminución de la variabilidad del ritmo cardíaco (HRV), y el aumento de la duración y la variabilidad de la actividad eléctrica cardíaca ventricular (intervalo QT) son indicativos de un mayor riesgo cardíaco 1-4. En modelos animales, es interesante comparar estos ECG derivados de las variables y la susceptibilidad a las arritmias inducidas experimentalmente. La infusión intravenosa de la aconitina agente arritmogénica ha sido ampliamente utilizada para evaluar la susceptibilidad a las arritmias en una serie de condiciones experimentales, incluyendo los modelos animales de depresión y la hipertensión 5 6, 7 y después del ejercicio la exposición a contaminantes del aire 8, así como la determinación de los antiarrítmicos eficacia de los agentes farmacológicos 9,10. Cabe señalar que la dispersión del intervalo QT en el ser humano es una medida de la variación del intervalo QT en el conjunto de los cables de un estándar de ECG de 12 derivaciones. En consecuencia, la medida de la dispersión del intervalo QT en el ECG de dos derivaciones en la rata se describe en este protocolo es diferente a la calculada a partir de registros de ECG humanos. Esto representa una limitación en la traducción de los datos obtenidos de los roedores a la medicina clínica humana. Estado de mal epiléptico (SE) es un ataque o una serie de convulsiones recurrentes continua de más de 30 min 11,12 11,12, y los resultados de la mortalidad en un 20% de los casos 13. Muchas personas sobreviven de la SE, pero mueren dentro de 30 días 14,15. El mecanismo (s) de este retraso en la mortalidad no se entiende completamente. Se ha sugerido que las arritmias ventriculares letales contribuir a muchas de estas muertes 14-17. Además de la SE, los pacientes que experimentan convulsiones se repiten espontáneamente, la epilepsia, es decir, están en riesgo de muerte súbita prematura e inesperada asociadas con la epilepsia (SUDEP) 18. Al igual que con SE, los mecanismos precisos de mediación SUDEP no se conocen. Se ha propuesto que las anomalías ventriculares y las arritmias que resulta hacer una contribución significativa 18-22. Para investigar los mecanismos de las convulsiones relacionadas con la muerte cardiaca, y la eficacia de las terapias cardioprotectoras, es necesario obtener tanto los indicadores de ECG derivados de los riesgos y evaluar la susceptibilidad a las arritmias cardiacas en modelos animales de trastornos convulsivos 23-25. A continuación se describen los métodos para la implantación de electrodos de ECG en ratas Sprague-Dawley de laboratorio (Rattus norvegicus), después de SE, recopilación y análisis de registros de ECG, y la inducción de arritmias durante la infusión intravenosa de aconitina. Estos procedimientos se pueden utilizar para determinar directamente las relaciones entre los ECG derivado de las medidas de la actividad eléctrica cardiaca y la susceptibilidad a las arritmias ventriculares en modelos de rata de los trastornos convulsivos, o cualquier otra patología asociada con mayor riesgo de muerte cardiaca repentina.

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

Técnicas para la medición de la actividad eléctrica del corazón mediante el electrocardiograma (ECG), y el análisis de factores de riesgo cardíaco y la susceptibilidad a las arritmias siguiente estado de mal epiléptico (SE) en la rata se describen.

Métodos de evaluación de ECG de los indicadores de riesgo cardiaco, y la susceptibilidad a arritmias inducidas por aconitina en ratas después de Estado epiléptico

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

methods-for-ecg-evaluation-indicators-cardiac-risk-susceptibility-to

Research

JoVE Journal

Medicine

17.6K vistas.  University of Utah. Técnicas para la medición de la actividad eléctrica del corazón mediante el electrocardiograma (ECG), y el análisis de factores de riesgo cardíaco y la susceptibilidad a las arritmias siguiente estado de mal epiléptico (SE) en la rata se describen.

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.

Ascendente aórtica Constricción en ratas para la Creación de la sobrecarga de presión hipertrofia cardíaca Modelo

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

Investigación

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 detección precoz de la disfunción renal hemodinámico inducido por medicamentos Usando tecnología ecográfica en ratas

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.

Resonancia Magnética Cardíaca para la Evaluación del Trombo Cardíaco Sospechoso: Técnicas Convencionales y Emergentes

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.

Evaluación ecocardiográfica de la anatomía cardíaca y la función en ratas adultas

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;

Método invasivo semiseminal para inducir el infarto de miocardio en ratas y la evaluación de la función cardíaca mediante un sistema cardíaco de trabajo aislado

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.

Análisis de registros de electrocardiografía a largo plazo para detectar arritmias en ratones

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

Analysis of Raw and Processed Cyperi Rhizoma Samples Using Liquid Chromatography-Tandem Mass Spectrometry in Rats with Primary Dysmenorrhea

Cyperi rhizoma (CR) is widely used in gynecology and is a general medicine for treating women's diseases in China. Since the analgesic effect of CR is enhanced after processing with vinegar, CR processed with vinegar (CRV) is generally used clinically. However, the mechanism by which the analgesic effect is enhanced by vinegar processing is unclear. In this study, the ultra-high pressure liquid chromatographytandem mass spectrometry (UPLC-MS/MS) technique was used to examine changes in the blood levels of the exogenous constituents and metabolites between CR-treated and CRV-treated rats with dysmenorrhea. The results revealed differing levels of 15 constituents and two metabolites in the blood of these rats. Among them, the levels of (-)-myrtenol and [(1R,2S,3R,4R)-3-hydroxy-1,4,7,7-tetramethylbicyclo[2.2.1]hept-2-yl]acetic acid in the CRV group were considerably higher than in the CR group. CRV reduced the level of 2-series prostanoids and 4-series leukotrienes with proinflammatory, platelet aggregation, and vasoconstriction activities and provided analgesic effects by modulating arachidonic acid and linoleic acid metabolism and the biosynthesis of unsaturated fatty acids. This study revealed that vinegar processing enhances the analgesic effect of CR and contributes to our understanding of the mechanism of action of CRV.

Here, a comparative analysis of raw and processed Cyperi rhizoma (CR) samples is presented using ultra-high performance liquid chromatography-high-resolution tandem mass spectrometry (UPLC-MS/MS) in rats with primary dysmenorrhea. The changes in blood levels of the metabolites and the sample constituents were examined between rats treated with CR and CR processed with vinegar (CRV).

Análisis de muestras crudas y procesadas de rizoma de Cyperi utilizando cromatografía líquida-espectrometría de masas en tándem en ratas con dismenorrea primaria

Cyperi rhizoma (CR) is widely used in gynecology and is a general medicine for treating women's diseases in China. Since the analgesic effect of CR is ...

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.

Trasplante de corazón abdominal heterotópico modificado y un nuevo modelo de regurgitación aórtica en ratas

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

Manipulación estandarizada de Tuina para la artrosis de rodilla en ratas

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.

Autor destacado: Entendiendo el mecanismo de la manipulación de la tuina en ratas 

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.

Manipulación de Tuina para reducir la inflamación y la pérdida de cartílago en ratas con artrosis de rodilla

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