Biz Dr Helio Salgado, Renata Lataro ve Mauro de Oliveira, kurulum işlemini sırasında cömert yardım için Ribeirão Preto, Sao Paulo ve Dr Ben Janssen, Kardiyovasküler Araştırma Enstitüsü Maastricht, Maastricht Üniversitesi, Üniversitesi Tıp Fakültesi ederim. Bu çalışma SDC FONDECYT hibe N ° 11090114 tarafından desteklenmiştir

Protokol Facultad de Medicina Clinica Alemana-Universidad del Desarrollo ve Etik Komitesi tarafından onaylandı. I. Dobutamin İnfüzyon hazırlamak <ol><li> 500 ug / ml dobutamin bir stok çözeltisi elde etmek için, steril distile su, 20 ml dobutamin 10 mg eritilir. -20 ° C&#39;de kısım ve mağaza Bu çözelti 3 ay için en azından kullanılabilir. </li><li> Oda sıcaklığında dobutamin stok çözeltisi bir kısım çözülme. </li><li> Dobutaminin (ug / ml) = vücut ağırlığı x 0.2: formül kullanılarak hesaplanır konsantrasyon dobutamin çalışma çözeltisi, elde etmek için, steril% 0.9 NaCI içinde dobutamin stok çözeltisi seyreltilir. </li><li> Dobutamin çalışma çözeltisi ile 1 ml şırınga 29Gx1 / 2 &quot;doldurun. </li><li> Bir 20 cm PE-10 tüp içine şırınga iğnesi yerleştirin. </li><li> Üreticinin talimatları izleyerek infüzyon pompası şırınga ayarlayın. </li><li> Bir adımda rampa infüzyon ayarlama6 adımlar için, her adım için 10 ul / dak artışla biçimi-to-adım. </li></ol> II. Basınç Sensörü hazırlanması <ol><li> En az 15 dakika boyunca 37 ° C &#39;de steril su içinde sinyal kayması, batırmak basınç sensörü en aza indirilmesi. Bu hidrostatik basınç basınç sensörü etkiler önlemek için, daha fazla 0.5 cm derinliğinde kateter emmek etme. </li><li> Elektronik 25 ve 100 mmHg basınç sensörü kalibre. Elektrik girişi (Volt) basınç sinyali (mmHg) dönüştürülür. </li><li> 2 k / s örnekleme hızı ayarlayın ve 100 Hz&#39;de kesilerek filtre alçak geçiren kullanın. Basınç sinyali sıfıra mmHg olarak ayarlayın. </li><li> Sonda ucundan 15 mm işaretleyin. Giriş noktasından kalp ulaşmak için Distant sol ventrikül içine kateter varlığı tespit, ekokardiyografi ile tahmin edilmiştir. </li></ol> III. Kateterizasyon için Fare hazırlanması <ol><li> Ağırlık C57BL / 6 erkek fareler, haftalık 30-32. </li><li> Intraperitoneal 60 mg / kg ketamin ve 4 mg / kg ksilazin 1 enjekte edilir. Not: Diğer anestezikler, örneğin, kullanılan olabilir: 350 - 450 mg / kg avertin, 50 mikrogram / ​​pentobarbital kg veya 1.5 - 2% izofluran 2-3. </li><li> Elektrikli ustura ile boyun Tıraş. </li><li> Isıtılmış bir izotermal ısıtma plakası üzerine sırtüstü pozisyonda anestezi fare yerleştirin. Kağıt bant ile bacaklarda sabitleyin. </li><li> Tam sedasyon onaylamak için bir ayak tutam gerçekleştirin. </li><li> Yavaşça vücut sıcaklığını izlemek için bir rektal prob yerleştirin. Vaselinized prob kullanılması önerilir. </li><li> Vücut ısısı 37 farklıysa ° C ± 0.5 ° C, ısıtma plakası yoluyla ayarlayabilirsiniz. </li><li> Oksijen kaynağı yakınında fare burun koyun. </li><li> Stereomikroskop altında fare boyun bölgesinde yerleştirin. </li></ol> IV. Veri Toplama <ol><li> LabChartPro 7 yazılımı, basınç kayıt için tek kanallı ve kalp hızı için bir kanal (İK) seçinkaydı. Ikincisi için, seçenek &quot;Döngüsel Ölçümleri&quot; ve hızı gibi kurulum ölçümü seçin. </li><li> 0 ila 150 mmHg: basınç kanalı için ölçek aralığı ayarlayın. </li><li> 200 ila 600 bpm For: HR kanal ölçek aralığı ayarlayın. </li><li> Kayıt başlamak için start tuşuna basınız. </li><li> Prosedürleri, örneğin yapılan gösteren yorumlarla takın: anestezi yönetimi, değişiklikler solunum, dobutamin infüzyonu, dobutamin konsantrasyon başlar. </li></ol> V. Kalp Kateterizasyonu 4,5 <ol><li> Çene yakın sağ tarafında küçük bir kesi yapın. Makas deri-kas bağ dokusu ayırmak ile. </li><li> Trakeanın sağ tarafta - bir uzunlamasına diseksiyon (2 cm 1.5) gerçekleştirin. Trakea yakınındaki sağ karotis arter ortaya koymak için, kavisli bir forseps ile bağ dokusu, yağ ve kas ayırın. </li><li> Karotis arter maruz hayvan sağ tarafına bir genişletici yerleştirin. Vurmalıkalp tarafından oluşturulan basınç arter tarafından bulunması kolaylaşmaktadır. Koyu kırmızı juguler ven, sağ tarafta. </li><li> Kavisli bir forseps ile bitişik dokulardan arter ayırın. Bir beyaz ipliği andıran vagus siniri, arter boyunca yatıyor. </li><li> 6/0 ipek iplik ve &quot;çift&quot; bir 20 cm parça kesin. </li><li> Soldan sağa arter altındaki &quot;çift&quot; iplik geçirin. Ayrı ayrı uçları elde etmek için, iplik kes. </li><li> Arter altında üçüncü bir iş parçacığı (10 cm) Min. </li><li> Başlığına yakın konumlandırılmış parçacığı sıkı bir düğüm ve daha distal iplik gevşek bir tek bağla. </li><li> Orta iplik gevşek bir düğüm ve bir kağıt bant ile ısıtma pedi için orta iplik sağ ucunu sabitleyin. </li><li> Steril% 0.9 NaCl bırakarak karotis arter nemli tutun. Pamuk tomurcukları ile sıvı aşırı kurumasını bekleyin. </li><li> Bir hemostat klemp ile alt iplik gerin. </li><li> P hemostat makas konumunu saptamakkan akışı tıkamak için, karın derisi Santimleme üst iplik germe. Arter çevresinde bağ dokusu çıkarıldığından emin olun. Arter kan dolu ve nabız yoksun olmalıdır. Arter üzerinde bir tork kuvveti üreten Konuları önleyin. </li><li> Bir Vannas mikro-makas ile arterin alt kısmına yakın bir kesit nick olun. Kan damlaları dökülen edilecektir. </li><li> Karotis arter içine kateter yerleştirin. Tüm basınç sensörü tanıtmak için emin olun. Hiçbir kan kaybı olduğunu doğrulayın. </li><li> Nazikçe yerinde tutmak kateter için, orta düğüm iplik ayarlayın. Çok fazla sıkıştırmak etmeyin, basınç sensörü çok kırılgandır. </li><li> Hayvanın karın hemostat makas bırakın. </li><li> Kan kaybını önlemek için, el ile kateter tutun ve orta iplik itme. Not: arter kan dolu olmalıdır. </li><li> Kaydı basınç sinyalleri başlayın. </li><li> Kateter içinde olduğunda,arteriyel basınç sinyali 60-70 100-120 mmHg dalgalanır. Basıncı sinyalinin şekli Şekil 1.A. Not gösterilmiştir: Eğer ilgilenen varsa sinyal en az 5 dakika boyunca sabit ise, bu kez noktada arter basıncı kaydedebilirsiniz. HR değerleri kayıt sinyali 30 saniye arayla dikkate basınç dalga elde edilmiştir. Bu soruşturma hedefleri doğrultusunda, İK doğrudan ölçümü için de bir EKG yöntemi kullanmak mümkündür. </li><li> Yavaşça basınç sinyali (Şekil 1.B) şeklinde bir değişiklik gözlemlemek için kateter yukarıya doğru itilir. Kateter sol ventrikül içine sonra, basınç sinyali 0 100-120 mmHg dalgalanır. Bu kateter kaydırın zor ise, iki parmak ile hayvan göğüs çimdik. </li><li> Sürekli nefes hızı, vücut ısısı, anestezi seviyesi ve basınç sinyalini kontrol. Hepsi de sabit kalmalıdır. </li></ol> VI. Dobutamin infüzyonu <ol><li&gt; Juguler ven kateterizasyonu için onun perforasyonu önlemek amacıyla, damar çevresinde geri soyma adipoz doku emin olun. Ven oklüzyonu için cerrahi prosedür karotid arter için gösterilen prosedüre benzer. </li><li> Damar içine PE-10 tüp tanıtın. Kan akımı onaylayın geriye şırınganın pistonu hareket engellenmez. </li><li> Dobutamin infüzyonu 10 ul / dk ile başlar ve 60 ul / dk ile bitiriyoruz. Her adımda, infüzyon hızı 2 dakika 6 için korunur. </li><li> Son dobutamin dozdan sonra, anestezi, bir doz aşımı ile hayvan ötenazi. </li></ol> VII. Veri Analizi <ol><li> Veri analizi için, ilgi kayıtlı veri bölümünü seçin. Basınç sinyali stabil olduğu bir zaman aralığı dikkate aldığınızdan emin olun. </li><li> Kan Basıncı modülü Kurulum simgesini seçin. Basıncı sinyalinin seçilen türü belirtin. </li><li> Otomatik LabChartPro 7 yazılımı görüntüler demek, maksimumve HR için minimum değerler, sistolik basıncı (P max), diyastolik kan basıncı (P min), diyastol sonu basıncı (EDP), maksimal pozitif basınç gelişimi (dP / dtmax) ve maksimal negatif basınç gelişimi (dP / dt min). Buna ek olarak, kalp parametrelerini basınç izleme üzerinde tasvir edilebilir. </li></ol>

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	<li>Hart, C. Y., Burnett, J. C., Redfield, M. M. <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+avertin+versus+xylazine-ketamine+anesthesia+on+cardiac+function+in+normal+mice.">Effects of avertin versus xylazine-ketamine anesthesia on cardiac function in normal mice.</a> Am. J. Physiol. Heart Circ. Physiol. 281, H1938-H1945 (2001).</li><li>Janssen, B. J., et al. <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+anesthetics+on+systemic+hemodynamics+in+mice.">Effects of anesthetics on systemic hemodynamics in mice.</a> Am. J. Physiol. Heart Circ. Physiol. 287, H1618-H1624 (2004).</li><li>Lorenz, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+guide+to+evaluating+cardiovascular,+renal,+and+pulmonary+function+in+mice.">A practical guide to evaluating cardiovascular, renal, and pulmonary function in mice.</a> Am. J. Physiol. Regul. Integr. Comp. Physiol. 282, R1565-R1582 (2002).</li><li>Lorenz, J. N., Robbins, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+intraventricular+pressure+and+cardiac+performance+in+the+intact+closed-chest+anesthetized+mouse.">Measurement of intraventricular pressure and cardiac performance in the intact closed-chest anesthetized mouse.</a> Am. J. Physiol. 272, H1137-H1146 (1997).</li><li>Nemoto, S., DeFreitas, G., Carabello, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+catheterization+technique+in+a+closed-chest+murine+model.">Cardiac catheterization technique in a closed-chest murine model.</a> Contemp. Top. Lab Anim. Sci. 42, 34-38 (2003).</li><li>Daniels, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impaired+cardiac+functional+reserve+in+type+2+diabetic+db/db+mice+is+associated+with+metabolic,+but+not+structural,+remodelling.">Impaired cardiac functional reserve in type 2 diabetic db/db mice is associated with metabolic, but not structural, remodelling.</a> Acta Physiol. (Oxf). 200, 11-22 (2010).</li><li>De Celle, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+structural+and+functional+consequences+of+cardiac+ischaemia-reperfusion+injury+in+vivo+in+mice.">Long-term structural and functional consequences of cardiac ischaemia-reperfusion injury in vivo in mice.</a> Exp. Physiol. 89, 605-615 (2004).</li><li>Huntgeburth, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transforming+growth+factor+beta+oppositely+regulates+the+hypertrophic+and+contractile+response+to+beta-adrenergic+stimulation+in+the+heart.">Transforming growth factor beta oppositely regulates the hypertrophic and contractile response to beta-adrenergic stimulation in the heart.</a> PLoS One. 6, e26628 (2011).</li><li>Reddy, A. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+function+in+young+and+old+Little+mice.">Cardiac function in young and old Little mice.</a> J. Gerontol. A. Biol. Sci. Med. Sci. 62, 1319-1325 (2007).</li><li>Christoffersen, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+lipid+accumulation+associated+with+diastolic+dysfunction+in+obese+mice.">Cardiac lipid accumulation associated with diastolic dysfunction in obese mice.</a> Endocrinology. 144, 3483-3490 (2003).</li></ol>

Çıkar çatışması ilan etti.

Dobutamin ile tetiklenen ve kardiyak kateterizasyon ile takip Kalp stres testi zahmetli. Bununla birlikte, burada protokolü takip tanımlamak ve eğitim kısa bir süre ile, tek bir deneyde geçen yaklaşık bir saat içinde altı hemodinamik parametreleri değerlendirmek mümkündür. Sunulan burada protokol kritik adımlar kan damarlarının cannulations vardır. Karotid arter kanülasyonu ile ilgili olarak, yapılan kesi üç doku arter katmanları, ve kateter geçişine izin vermek içi...

<table border="1"><tbody><tr><td></td><td></td><td></td><td> Reaktifler </td></tr><tr><td> PE-50/10 </td><td> Warner Instruments </td><td> 64-0752 </td><td></td></tr><tr><td> İpek ipliği 6/0 HR17 </td><td> Tagum </td><td> SN0713K </td><td></td></tr><tr><td> Xylacin 20 mg / ml </td><td> Laboratorio Centrovet </td><td></td><td></td></tr><tr><td> Ketamin 100 mg / ml </td><td> Sürükle Pharma </td><td></td><td></td></tr><tr><td> Sodyum klorür% 0.9 &#39; </td><td> Lab Sanderson SA </td><td></td><td></td></tr><tr><td> Dobutamin hidroklorür </td><td> Sigma-Aldrich </td><td> D0676 </td><td></td></tr><tr><td> Şırınga U-100 İnsülin 29G x ½ &quot; </td><td> Terumo Medical Co </td><td></td><td></td></tr><tr><td> Mikro 11,5 cm Stil 7 Diseksiyon Forseps </td><td> LawtonMedizintechnik </td><td> 09-0959 </td><td></td></tr><tr><td> Graefe Forseps CVD 0.7mm 7cm </td><td> Lawton Medizintechnik </td><td> 62-0263 </td><td></td></tr><tr><td> Kelepçeleri Dieffenbach bulldog Cl Str 38 mm </td><td> Lawton Medizintechnik </td><td> 60-010 </td><td></td></tr><tr><td> Vannas Makas 8 cm Str Fh </td><td> Lawton Medizintechnik </td><td> 63-1400 </td><td></td></tr><tr><td></td><td></td><td></td><td> Ekipman </td></tr><tr><td> SPR-671 Mikro-Tip Basınç kateter </td><td> Millar aletleri </td><td> 840-6719 </td><td></td></tr><tr><td> PKB-2000 Basınç Kontrol Ünitesi </td><td> Millar aletleri </td><td> 880-0129 </td><td></td></tr><tr><td> PowerLab 4/30 </td><td> ADinstruments Pty Ltd </td><td> ML866 </td><td></td></tr><tr><td> LabChartPro 7 </td><td> ADinstruments Pty Ltd </td><td> MLU260 / 7 </td><td></td></tr><tr><td> Legato200 İnfüzyon Pompası </td><td> KdScientific </td><td> KD-KDS210P </td><td></td></tr><tr><td> Tcat-2LV Sıcaklık kontrolörü ve izotermal ısıtma plakası </td><td> PhysiTemp aletleri A.Ş. </td><td></td><td></td></tr><tr><td> Medikal Oksijen kaynağı </td><td> Indura </td><td></td><td></td></tr><tr><td> Rektal prob </td><td> ADinstruments Pty Ltd </td><td> MLT1404 </td><td></td></tr><tr><td> Trinoküler Mikroskop, eksenel aydınlatma </td><td> LW Scientific </td><td> Z2B-TRI-ETNE, ILP-1502-LTS1, ILP-1502-DGGF </td><td></td></tr></tbody></table>

cardiac stress test induced by dobutamine and monitored by cardiac catheterization in mice

Dobutamin arter (β 2) olarak ifade reseptörlerine göre kalp (β 1) olarak ifade reseptörü için yüksek bir afiniteye sahip bir β-adrenerjik agonistidir. Sistemik olarak uygulandığında, kardiyak tüketimini artırır. Böylece, dobutamin potansiyel enfarktüs riski anormal ritmi veya iskemik alanlar unmasks. Bir kardiyak stres testi sırasında kalp fonksiyonlarının izlenmesi ekokardiyografi veya kalp kateterizasyonu da yapılabilir. İkincisi bu eski bir invaziv, ancak daha doğru ve bilgilendirici bir tekniktir. Kalp atım hızı (KAH), sistolik basınç, diyastolik basınç, diyastol sonu basıncı, maksimal pozitif basınç: Kalp stres testi dobutamin ile tetiklenen ve burada açıklandığı gibi başarılı kardiyak kateterizasyon tarafından izlenen tek bir deneyde, aşağıdaki hemodinamik parametrelerin ölçümünde, izin geliştirme (dP / dtmax) ve maksimal olumsuz basınure geliştirme (dP / dt min), bazal şartlarda ve dobutamin artan dozlarda altında. Beklendiği gibi, normal farelerin biz İK, dP / dt max ve dP / dt min bir dobutamin doza bağlı artış gözlendi. Ayrıca, en yüksek dozda, yüksek yağ içerikli diyet ile endüklenen aşırı şişman farelerde kalp dekompensasyon ortaya çıkmasından sonra (12 ng / g / dak) test edilmiştir.

Arteriyel basınç sinyali sistolik ve diyastolik kan basıncı ile tanımlanır. Basınç sensörü sol ventrikül içinde olduğunda, onun basınç (LVP) dalga diyastolik basınç sıfır bir damla ve ventrikül kasılma öncesinde sol atriyal kasılma (Şekil 1) ile karakterizedir. Mevcut durum, ketamin-ksilazin anestezisi normal farelerin 280 HR ± 24, 107 P maks ± 8, 5 P dk ± 1, 14 ± 2 EDP, dP / 6081 dt max ± 365 ve dP / dt min vardı 5230 ± 526. </p...

Watch this Scientific Journal Video about Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice at JoVE.com

Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice

Biz dobutamin ile tetiklenen ve normal farelerde kalp kateterizasyonu tarafından izlenen bir kardiyak stres testi gerçekleştirmek için protokol açıklar. Ayrıca yüksek yağlı diyet bağlı obez farelerde subklinik kardiyak hastalık meydana çıkarmak için uygulama göstermektedir.

Kardiyak Stres Testi Dobutamin İndüklemiş ve Farelerde Kalp Kateterizasyonu tarafından İzlenen

Dobutamine is a &beta;-adrenergic agonist with an affinity higher for receptor expressed in the heart (&beta;1) than for receptors expressed in the ...

cardiac-stress-test-induced-dobutamine-monitored-cardiac

Research

JoVE Journal

Medicine

18.0K Görüntüleme.  Clínica Alemana Universidad del Desarrollo. Biz dobutamin ile tetiklenen ve normal farelerde kalp kateterizasyonu tarafından izlenen bir kardiyak stres testi gerçekleştirmek için protokol açıklar. Ayrıca yüksek yağlı diyet bağlı obez farelerde subklinik kardiyak hastalık meydana çıkarmak için uygulama göstermektedir.

Video: Cardiac Stress Test Induced by Dobutamine and Monitored by Cardiac Catheterization in Mice

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

Bowditch Efekt incelenmesi: Basınç Hacim İlişkisi Tedbir Fare Kardiyak Kateterizasyon

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

Tıp

Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable noninvasive method is essential to assess real-time cardiac morphological and functional changes in animal models of heart disease. Transthoracic echocardiography represents an important tool for noninvasive assessment of cardiac structure and function2. Here we used a high-resolution ultrasound imaging system to monitor myocardial remodeling and heart failure progression over time in a mouse model of TAC. B-mode, M-mode, and Doppler imaging were used to precisely assess cardiac hypertrophy, ventricular dilatation, and functional deterioration in mice following TAC. Color and pulse wave (PW) Doppler imaging was used to noninvasively measure pressure gradient across the aortic constriction created by TAC and to assess transmitral blood flow in mice. Thus transthoracic echocardiographic imaging provides comprehensive noninvasive measurements of cardiac dimensions and function in mouse models of heart disease.

The goal of this protocol is to noninvasively assess cardiac structural and functional changes in a mouse model of heart disease created by transverse aortic constriction, using B- and M-mode echocardiography and color/pulse wave Doppler imaging.

Ekokardiyografik Imaging tarafından Enine Aort Konstrüksiyon Mouse Modeli Kardiyak Morfolojik Değerlendirilmesi ve Fonksiyonel Değişiklikler

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable ...

Echocardiographic Approaches and Protocols for Comprehensive Phenotypic Characterization of Valvular Heart Disease in Mice

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in rodents, with detailed descriptions of the appropriate methods for anesthesia, the echocardiographic windows used, the imaging planes and probe orientations for image acquisition, the methods for data analysis, and the limitations of emerging technologies for the evaluation of cardiac and valvular function. Importantly, we also highlight several future areas of research in cardiac and heart valve imaging that may be leveraged to gain insights into the pathogenesis of valve disease in preclinical animal models. We propose that using a systematic approach to evaluating cardiac and heart valve function in mice can result in more robust and reproducible data, as well as facilitate the discovery of previously underappreciated phenotypes in genetically-altered and/or physiologically-stressed mice.

This protocol provides a detailed description of the echocardiographic approach for comprehensive phenotyping of heart and heart valve function in mice.

Farelerde Kalp Kapak Hastalıkları Kapsamlı Fenotipik Karakterizasyonu için ekokardiyografik Yaklaşımlar ve Protokoller

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in ...

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality worldwide. In humans, a pathologic occlusion forms in a coronary artery and reperfusion of that occluded artery is considered essential to maintain viability of the myocardium at risk. Although essential for myocardial recovery, reperfusion of the ischemic myocardium creates its own tissue injury. The physiologic response and healing of an ischemia/reperfusion injury is different from a chronic occlusion injury. Myocardial ischemia/reperfusion injury is gaining recognition as a clinically relevant model for myocardial infarction studies. For this reason, parallel animal models of ischemia/reperfusion are vital in advancing the knowledge base regarding myocardial injury. Typically, ischemia of the mouse heart after left anterior descending (LAD) coronary artery occlusion is confirmed by visible pallor of the myocardium below the occlusion (ligature). However, this offers only a subjective way of confirming correct or consistent ligature placement, as there are multiple major arteries that could cause pallor in different myocardial regions. A method of recording electrocardiographic changes to assess correct ligature placement and resultant ischemia as well as reperfusion, to supplement observed myocardial pallor, would help yield consistent infarct sizes in mouse models. In turn, this would help decrease the number of mice used. Additionally, electrocardiographic changes can continue to be recorded non-invasively in a time-dependent fashion after the surgery. This article will demonstrate a method of electrocardiographically confirming myocardial ischemia and reperfusion in real time.

During murine myocardial ischemia/reperfusion surgery, correct placement of the occluding ligature is typically confirmed by visible observation of myocardial pallor. Herein, a method of electrocardiographically confirming ischemia and reperfusion, to supplement observed myocardial pallor, is demonstrated in male C57Bl/6 mice.

Yüzey Pad Elektrokardiyografi kullanılması Farelerde Miyokard İskemi ve Reperfüzyon Hasarı Onayı

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality ...

Real-time Pressure-volume Analysis of Acute Myocardial Infarction in Mice

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any potential therapeutic approach directed against acute left ventricular (LV) dysfunction. Current imaging modalities (e.g., echocardiography and magnetic resonance imaging) have several limitations since data on LV pressure cannot directly be measured. LV catheterization in mice undergoing coronary artery occlusion could serve as a novel method for a real-time evaluation of LV function.
At the beginning of the procedure, mice were anesthetized followed by endotracheal intubation. For LV catheterization, the right carotid artery was exposed via middle-neck incision. The catheter was introduced and placed into the LV cavity. Left thoracotomy was conducted and the left main coronary artery (LCA) was ligated. To induce reperfusion, the suture was released after 45 min. Pressure-volume data was recorded at all times.
Ligation of the LCA caused a decrease in LV systolic function as evidenced by a 30% reduction in stroke volume, LV ejection fraction (EF), and cardiac output. Maximum dP/dt as a parameter for LV contractility was also significantly reduced and diastolic function was severely impaired (minimum dP/dt -40%). Reperfusion over a period of 20 min did not lead to a complete recovery of LV function.
Real-time pressure-volume analysis served as a valid procedure for monitoring cardiac function during acute myocardial infarction in mice. Maintaining stable anesthesia and a standardized surgical approach was crucial to ensure valid results. As the early phase of acute myocardial infarction is critical for morbidity and mortality, the delineated method could be beneficial for preclinical evaluation of new strategies for cardioprotection.

Acute myocardial infarction in mice induces acute but incompletely characterized changes in left ventricular (LV) function. LV catheterization in mice undergoing coronary artery occlusion serves as a novel method for a real-time evaluation of LV function.

Akut miyokard infarktüsünde farelerde gerçek zamanlı basınç-hacim Analizi

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any ...

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles.
Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired using&#160;admittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

Presented here is a protocol to assess biventricular heart function in mice by generating pressure-volume (PV) loops from the right and left ventricle in the same animal using closed chest catheterization. The focus is on the technical aspect of surgery and data acquisition.

Farelerde Kapalı Göğüs Kateterizasyonu ile Kardiyak Fonksiyon ve Basınç-Hacim Döngülerinin Biventriküler Değerlendirmesi

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) ...

A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed cardiac performance in the absence of hypertension, valvular, congenital, or ischemic heart diseases, and which may be related to infection, autoimmune or metabolic abnormalities, or family inheritance. It can progress into congestive heart failure with a poor prognosis. Doxorubicin (Dox) is widely employed as a chemotherapeutic drug, but its use is limited because it causes DCM-like changes of the myocardium. Its myocardial toxicity is attributed to oxidative stress, chronic inflammation, and cardiomyocyte apoptosis. A model of DCM exploiting these Dox-induced DCM symptoms has not been established.

Described is a protocol to establish a Doxorubicin-induced dilated cardiomyopathy (DCM) model in mice via long-term intraperitoneal injection of Doxorubicin.

Vivo'da Genişlemiş Kardiyomiyopatinin Doxorubicin Kaynaklı Murine Modeli

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed cardiac ...

Revealing Subtle Changes in Cardiac Function using Transthoracic Dobutamine Stress Echocardiography in Mice

Left ventricular (LV) dysfunction paves the final pathway for a multitude of cardiac disorders. With the non-invasive high-frequency transthoracic dobutamine stress echocardiography in humans, a reductionist investigation approach to unmask subtle changes in cardiac function has become possible. Here, we provide a protocol for using this technique in mice to facilitate expanded analysis of LV architecture and function in physiology and pathology enabling the observation of alterations in models of cardiac disease hidden in unstressed hearts. This investigation can be performed in one and the same animal and allows both, basal and pharmacologically stress-induced measurements. We outline detailed criteria for appropriate anesthesia, imaging-based LV analysis, consideration of intra- and interobserver variability, and obtaining positive inotrope response that can be attained in mice after intraperitoneal injection of dobutamine under near physiological conditions. To recapitulate the characteristics of human physiology and disease in small animal models, we highlight critical pitfalls in evaluation, e.g., a pronounced Bowditch effect in mice. To further meet translational objectives, we compare stress-induced effects in humans and mice. When used in translational studies, attention must be paid to physiological differences between mice and human. Experimental rigor dictates that some parameters assessed in patients can only be used with caution due to restrictions in spatial and temporal resolution in mouse models.

Left ventricular dysfunction constitutes the final common pathway for a host of cardiac disorders. We here provide a detailed protocol of transthoracic dobutamine stress echocardiography approach for comprehensive evaluation of the left ventricular function of mouse models of cardiac disease as well as cardiac phenotyping.

Left ventricular (LV) dysfunction paves the final pathway for a multitude of cardiac disorders. With the non-invasive high-frequency transthoracic ...

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Regular physical exercise is a major contributor to cardiovascular health, influencing various metabolic as well as electrophysiological processes. However, in certain cardiac diseases such as inherited arrhythmia syndromes, e.g., arrhythmogenic cardiomyopathy (ACM) or myocarditis, physical exercise may have negative effects on the heart leading to a proarrhythmogenic substrate production. Currently, the underlying molecular mechanisms of exercise-related proarrhythmogenic remodeling are largely unknown, thus it remains unclear which frequency, duration, and intensity of exercise can be considered safe in the context of disease(s).
The proposed method allows to study proarrhythmic/antiarrhythmic effects of physical exercise by combining treadmill training with real-time monitoring of the ECG. Implantable telemetry devices are used to continuously record the ECG of freely moving mice over a period of up to 3 months both at rest and during treadmill training. Data acquisition software with its analysis modules is used to analyze basic ECG parameters such as heart rate, P wave duration, PR interval, QRS interval, or QT duration at rest, during and after training. Furthermore, heart rate variability (HRV) parameters and occurrence of arrhythmias are evaluated. In brief, this manuscript describes a step-by-step approach to experimentally explore exercise induced effects on cardiac electrophysiology, including potential proarrhythmogenic remodeling in mouse models.

Electrocardiogram (ECG) is the key variable to understanding cardiac electrophysiology. Physical exercise has beneficial effects but may also be harmful in the context of cardiovascular diseases. This manuscript provides a method of recording real-time ECG during exercise, which can serve to investigate its effects on cardiac electrophysiology in mice.

Farelerde koşu bandı eğitimi sırasında gerçek zamanlı elektrokardiyogram izleme

Regular physical exercise is a major contributor to cardiovascular health, influencing various metabolic as well as electrophysiological processes. ...

<meta charset="utf8"></head><body>Yüksek Yağlı Diyet ve STZ Enjeksiyonu ile Diyabetik Kardiyomiyopati için Murin Modeli

Modeling and Evaluation of Murine Diabetic Cardiomyopathy Model

The underlying pathophysiological mechanisms of diabetic cardiomyopathy (DbCM), a leading cause of mortality among patients with type 2 diabetes mellitus (T2DM), remain poorly understood. The myocardial toxicity associated with T2DM is attributed to factors such as lipotoxicity, glucotoxicity, oxidative stress, reduced cardiac efficiency, and lipoapoptosis. Compared to rats, mice offer greater accessibility, cost-effectiveness, and broader applicability for animal experiments. Insulin resistance and impaired insulin secretion are crucial factors in the pathophysiology of T2DM. We introduce a novel nongenetic murine model that replicates the progression of human DbCM induced by a combination of high-fat diet (HFD) feeding and streptozotocin (STZ) injection. In this study, we used wild-type C57BL/6J mice, administering an HFD regimen for 12 weeks, followed by intraperitoneal injections of STZ for an additional 12 weeks to induce characteristic manifestations of T2DM. We conducted oral glucose tolerance tests and measured serum insulin concentrations to confirm the development of insulin resistance and insufficient insulin secretion. Cardiac structure and function were rigorously assessed through noninvasive transthoracic echocardiography. Pathological characteristics were evaluated through Masson's trichrome staining and wheat germ agglutinin (WGA) staining, revealing pathological features related to DbCM. Therefore, we provide a robust and versatile method for establishing a nongenetic murine model of DbCM.

<meta charset="utf8"></head><body>Murin Diyabetik Kardiyomiyopati Modelinin Modellenmesi ve Değerlendirilmesi

This protocol outlines a method for inducing diabetic cardiomyopathy through a combination of high-fat diet feeding and streptozotocin injection. This approach aims to provide a reliable framework for scientific investigation into diabetic cardiomyopathy and to explore potential avenues for clinical treatment applications.

Murin Diyabetik Kardiyomiyopati Modelinin Modellenmesi ve Değerlendirilmesi

The underlying pathophysiological mechanisms of diabetic cardiomyopathy (DbCM), a leading cause of mortality among patients with type 2 diabetes mellitus ...