The authors have nothing to disclose.

이 프로토콜은 워싱턴 대학의 기관 동물 관리 및 사용위원회의 가이드 라인을 따른다. 1. 수술 절차 및 이미징을위한 준비 <ol><li> TAC 또는 가짜 수술에 따라 C57BL / 6 마우스는 이전 10 설명했다. </li><li> 일주일 TAC 또는 가짜 수술 후, 1 L / 분 O 2 혼합 2 % 이소 플루 란을 유도 챔버에 마우스를 마취. 발가락이나 꼬리 끼에 응답하지 않는하여 적절한 마취를 확인합니다. 마취 동안 건조를 방지하기 위해 눈에 수의학 연고를 사용합니다. 제모 크림을 적용하여 가슴 털을 제거합니다. 70 % 에탄올로 마우스 피부를 소독. </li><li> 앙와위에서 동물 처리 플랫폼에 마우스를 고정합니다. 1 L / 분, O2와 혼합 1 % 이소 플루 란 - 마취 일정한 수준을 유지하기 위해, 0.5을 제공하는 원추형 두부를 사용한다. </li><li> 마우스의 발에 전극 젤을 적용하고는 전극 패드에 테이프. </li><li> 체온을 모니터링하는 직장​​ 프로브를 삽입한다. 가열 패드 또는 램프를 통해 37 ℃의 체온을 유지한다. </li><li> 마우스 가슴, 심장 위에 놓인 주로 지역에 미리 예열 초음파 젤의 레이어를 적용합니다. 주 : 초음파 젤을 제거하고 이미지를 만드는 절차 후 멸균 거즈와 마우스를 건조. </li></ol> 대동맥 궁보기 2. 사용 B 모드 및 도플러 영상은 가로 대동맥 수축을 평가하는 <ol><li> 대동맥, 동맥 주요 가지, 및 협착 부위를 시각화하기 위해 대동맥 궁보기를 얻기 위해 B-모드 설정을 사용한다. <ol><li> 욕창 좌측 위치로 마우스를 회전 가능한 한 최대 플랫폼의 왼쪽을 기울인다. 수직으로 독립하여 초음파 변환기를 잡고 마우스의 턱을 향해 노치 가리키는 오른쪽 흉골 라인을 따라 가슴에 놓습니다. 참고 : 마우스 흉부를 압축하지 마십시오 transd을 내릴 때ucer; 압력의 최소량이 요구된다. </li><li> 견갑골의 수준에서 변환기를 기울여 대동맥 궁이보기에 올 때까지 약간 시계 방향으로 회전한다. 무명 동맥 (IA)과 왼쪽 경동맥 (LCCA) (그림 1)의 분기 사이에있는 가로 대동맥 수축 사이트를 관찰합니다. 참고 : 수축이 가짜로 작동하는 마우스에서 검출되지 않는다. </li></ol></li><li> 수축 사이트에서 혈액 흐름의 방향성과 속도를 모니터링하는 컬러 도플러 모드로 전환하기 위해 워크 스테이션에서 &quot;컬러 도플러&quot;버튼을 클릭합니다. 취득하고 &quot;시네 저장&quot;버튼을 클릭하여 이미지를 저장합니다. </li><li> 최고 속도로 협착 제​​트를 검색 할 수축 사이트에 바로 원위부 웨이브 도플러 모드, 장소 샘플 볼륨 (점선 커서 상자) 펄스로 전환하기 위해 &quot;PW 도플러&quot;버튼을 클릭 한 다음 &quot;PW 도플러&quot;버튼을 클릭 대동맥 FL 파형을 구하는흐름 및 측정 최대 속도 (그림 2). </li><li> 압력 구배 = 4 × V의 최대 2 : 변성 베르누이의 식을 이용하여 수축 위치에 걸쳐 압력 차이를 계산한다. 만 추가 분석을 위해 40 ~ 80 mmHg의 범위의 압력 구배와 마우스를 포함한다. </li></ol> 흉골 긴 축보기 3. 사용 B-모드와 M 모드 이미징 심장 크기 및 수축성을 평가하기 <ol><li> 마우스가 플랫폼에서 앙와위로 누워, 마우스의 머리에 노치 가리키는 수직 방식으로 변환기를 개최합니다. 왼쪽 흉골 라인에 가슴 평행에 변환기를 낮 춥니 30 ° 시계 반대 방향으로 돌립니다. </li><li> 심장의 전체 장축 &quot;시상&quot;보기를 얻기 위해 B 모드 이미지를 사용합니다. 트랜스 듀서의 각도를 조정하고 좌심실의 심실 중격 벽, 오른쪽 심실 벽의 약간의 부분을 시각화하는 깊이 초점을 맞 춥니 다. 에스심장 벽 두께 및 챔버 치수 이상 측정 이미지 집결지. &quot;심장 패키지&quot;를 사용하여 선택한 다음과 같은 IVS 또는 LVAW, LVID 및 LVPW 등의 매개 변수 및 측정을 얻기 위해 각각의 매개 변수에 해당하는 선을 그릴 이미지를 클릭. </li><li> 심장 벽의 움직임 패턴을 관찰하고 무 운동, 운동 감소증 및 비동기를 포함한 가능한 운동 이상, 확인합니다. 주 : 무 운동 각각 심장 벽의 이동 전체 및 부분 손실을 나타낸다 운동 감소증. 비동기 불규칙, 조정되지 않은 심장 벽의 움직임을 나타낸다. </li><li> 젖꼭지 근육의 수준에서 LV 벽에 수직으로 M 모드, 장소 M 모드 커서로 전환, 심장 크기와 분수 단축 (그림 3) 이후 측정을위한 이미지를 수집. </li></ol> 흉골 짧은 축보기, 심장 형태와 기능을 평가하기 위해 사용 B-모드와 M 모드 이미징 4. <ol><li> FR옴 흉골 긴 축보기, 트랜스 듀서 시계 방향으로 90 ° 회전하여 흉골 단축보기를 얻을 수 있습니다. 명확하게 보이는 오른쪽 (2, 4시 방향)에있는 유두 근육 모두, B-모드에서 마음의 수평 단면 &quot;가로&quot;보기를 제공하기 위해 변환기를 조정합니다. </li><li> M 모드로 전환 좌심실의 중간 수준에서 M 모드 축에 배치합니다. 취득 및 심장 벽의 두께, 실 치수 및 소수 단축 (그림 4) 이후 측정을위한 저장 이미지. &quot;심장 패키지&quot;를 사용하여, SAX IVS 또는 LVAW, LVID 및 LVPW 포함 (단축), 이미지를 클릭에서 선택 매개 변수 측정을 얻기 위해 각각의 매개 변수에 해당하는 선을 그립니다. 참고 : 여기에서 얻어진 측정은 흉골 긴 축보기 (그림 5)에서 얻은 것과 밀접하게 연관되어야합니다. </li></ol> 꼭대기 개의 챔버보기, 사용 5.수축기 및 이완기 기능을 평가하기 위해 도플러 영상 <ol><li> 화면 하단의 심방과 왼쪽과 오른쪽 심실을 시각화 꼭대기 사 실 뷰를 얻습니다. B 모드에서, 단축의 관점에서, 아래 각도로 마우스의 머리 플랫폼의 상부 좌측 코너를 기울 마우스의 오른쪽 어깨쪽으로 배향 변환기. 이 정점을 향해 찾고 마음의 &quot;코로나&quot;보기를 달성하기 위해 필수적이다. </li><li> B 모드에서 승모판 시각화 및 승모판의 끝에 샘플 볼륨 (점선 커서 박스)를 배치하는, 컬러 도플러 모드로 전환. </li><li> PW 도플러 모드로 전환 승모판을 통해 흐름 패턴을 평가합니다. 승모판 혈류의 방향 도플러 프로브 커서 평행 정렬. 최고 속도 (그림 6)를 결정하기 위해 프로브 각도보다 20 °를 사용합니다. </li><li> 나중에 측정을 위해 이미지를 저장합니다. &quot;심장 패키지&quot;를 사용하여 &quot;MV 흐름을 선택. &quot;각 매개 변수를 클릭하고 측정 값을 얻기 위해 줄을 해당 그릴 가능한 측정은 다음과 같습니다. 피크 E 속도 (초기 활성 심실 휴식과 충전을), (IVRT를 속도 (후반 심방 수축으로 작성), 승모판 isovolumic 이완과 수축 시간을 정점 IVCT 각각), 및 배출 시간 (ET). </li><li> MPI = (IVCT + IVRT) / ET에 의한 심근 성능 지수 (MPI)를 계산합니다. </li></ol> 동물의 6. 사후 절차 처리 <ol><li> 필요한 경우 복강 수술 동물에 진통 및 / 또는 멸균 생리 식염수를 제공합니다. </li><li> 동물이 발생하기 쉬운 위치에 가열 패드에 복구 할 수 있습니다. 이 흉골 드러 누움을 유지하기 위해 충분한 의식을 회복 할 때까지 무인 동물을 두지 마십시오. 완전히 회복 될 때까지 다른 동물의 회사에 절차를 거친 동물을 반환하지 않습니다. </li></ol>

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This work was supported in part by NIH/NHLBI grants R00HL0908076 and R01HL116507 (to Q.L.).

심장 초음파 널리 심장병 2,6의 설치류 모델에서 심장 기능을 평가하기 위해 사용되었다. 이러한 압력 볼륨 루프 측정 (11) 침입 또는 터미널 방법 비교 및 생체 심장 (12), 심 초음파가 살고있는 동물의 지속적인 심장 구조 및 기능 변화를 평가하기위한 강력하고 비 침습적 인 도구를 제공 작동합니다. 신뢰성있는 데이터를 얻기 위해,주의가 가열 장치 및 마취 레벨을 ...

Mouse models of heart disease, such as TAC and myocardial infarction (MI), have been proven to be valuable to study disease mechanisms as well as to develop novel therapeutic strategies3. TAC initially induces compensatory hypertrophy, but prolonged pressure overload leads to cardiac dilatation and heart failure4. The tightness of the aortic constriction directly determines the degree of cardiac hypertrophy and its transition to heart failure. Noninvasive and reliable measurement of pressure gradient across the aortic constriction is essential for the success of these studies. Doppler imaging has been used to assess pressure gradient produced by TAC5, which is a noninvasive alternative for catheter-based pressure measurement.
Echocardiography has been widely used to noninvasively measure cardiac morphology as well as systolic and diastolic function in mice6-8. Two-dimensional B-mode imaging is used to detect abnormal movements or structural changes of the heart. One-dimensional M-mode imaging is used for quantification of cardiac dimensions and contractility. Color and PW Doppler imaging has recently been used on rodent ultrasound, which has broad applications for echocardiography, including measurement of flow directionality and velocity, as well as systolic and diastolic performance9. 
Longitudinal real-time monitoring of cardiac function using echocardiography in B-mode, M-mode, color and PW Doppler mode provides comprehensive assessment of cardiac structure and function in mice under physiological and pathological conditions. Here we provide a detailed description of the use of echocardiographic imaging to monitor dynamic cardiac morphological and functional changes in mice following TAC or sham surgery.

<table><tbody><tr><td>Anesthesia equipment</td><td>Harvard Apparatus, 84 October Hill Road&lt;br/&gt; Holliston, MA</td><td>723015</td><td></td></tr><tr><td>Vevo 2100 Imaging System</td><td>VisualSonics Inc., 3080 Yonge Street Suite 6100, Box 66, Toronto, Ontario, Canada</td><td>Vevo 2100</td><td></td></tr><tr><td>Aquasonic ultrasound gel</td><td>Parker Laboratories, 286 Eldridge Rd, Fairfield, NJ&amp;nbsp;</td><td>03-50</td><td></td></tr><tr><td>Isoflurane</td><td>Piramal Healthcare, Inc, 3950 Schelden Circle&lt;br/&gt; Bethlehem, PA&amp;nbsp;</td><td>NDC 66794-017-25</td><td></td></tr><tr><td>F/air anesthesia gas filter unit</td><td>A.M. Bickford, Inc, 12318 Big Tree Rd, Wales Center, NY&amp;nbsp;</td><td>80120</td><td></td></tr></tbody></table>

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.

그림 1은 가짜 (그림 1A)를 실시 마우스 심장이나 TAC 수술 (그림 1B)의 대동맥 궁보기의 B 모드 이미지를 보여줍니다. 대동맥 궁, 무명 동맥, 경동맥을 왼쪽, 왼쪽 쇄골 하 동맥이 표시됩니다. 대동맥 협착이 TAC에 명확하게 볼 수 있습니다하지만 마음을 가짜 없습니다. 대동맥보기에서 컬러 도플러 이미지는 그림 2A에 표시됩?...

Watch this Scientific Journal Video about Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging at JoVE.com

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

이 프로토콜의 목적은 비 침습적 및 M B- 모드 초음파 심장 검진 및 컬러 / 맥파 도플러 촬상을 이용하여 횡 대동맥 수축에 의해 생성 된 심장 질환의 마우스 모델에서 심장 구조적 및 기능적 변화를 평가하는 것이다.

심 초음파 이미징에 의해 가로 대동맥 수축의 마우스 모델에서 심장 형태 학적 평가 및 기능 변경

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

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18.1K 조회수.  University of Washington.  이 프로토콜의 목적은 비 침습적 및 M B- 모드 초음파 심장 검진 및 컬러 / 맥파 도플러 촬상을 이용하여 횡 대동맥 수축에 의해 생성 된 심장 질환의 마우스 모델에서 심장 구조적 및 기능적 변화를 평가하는 것이다. 

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

Transthoracic Echocardiography in Mice

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,6 whereas TDI is used to measure the velocity of myocardial motion.7 Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.

마우스에 Transthoracic Echocardiography

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene ...

연구

의학

Murine Echocardiography and Ultrasound Imaging

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1 Echocardiography provides a powerful, non-invasive tool to serially assess cardiac morphometry and function in a living animal.2 However, using this technique on mice poses unique challenges owing to the small size and rapid heart rate of these animals.3 Until recently, few ultrasound systems were capable of performing quality echocardiography on mice, and those generally lacked the image resolution and frame rate necessary to obtain truly quantitative measurements. Newly released systems such as the VisualSonics Vevo2100 provide new tools for researchers to carefully and non-invasively investigate cardiac function in mice. This system generates high resolution images and provides analysis capabilities similar to those used with human patients. Although color Doppler has been available for over 30 years in humans, this valuable technology has only recently been possible in rodent ultrasound.4,5 Color Doppler has broad applications for echocardiography, including the ability to quickly assess flow directionality in vessels and through valves, and to rapidly identify valve regurgitation. Strain analysis is a critical advance that is utilized to quantitatively measure regional myocardial function.6 This technique has the potential to detect changes in pathology, or resolution of pathology, earlier than conventional techniques. Coupled with the addition of three-dimensional image reconstruction, volumetric assessment of whole-organs is possible, including visualization and assessment of cardiac and vascular structures. Murine-compatible contrast imaging can also allow for volumetric measurements and tissue perfusion assessment.

This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse. The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast imaging.

Murine Echocardiography 및 초음파 이미징

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1  ...

Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction4. To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential.
A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software.
Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic&#160;and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC.
Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.

Right ventricle (RV) dysfunction is critical to the pathogenesis of cardiovascular disease, yet limited methodologies are available for its evaluation. Recent advances in ultrasound imaging provide a noninvasive and accurate option for longitudinal RV study. Herein, we detail a step-by-step echocardiographic method using a murine model of RV pressure overload.

경 흉부 심 초음파에 의한 폐동맥 수축의 마우스 모델에서 마우스 오른쪽 심실 구조 및 기능의 평가

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, ...

Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart failure.1 TAC initially leads to compensated hypertrophy of the heart, which often is associated with a temporary enhancement of cardiac contractility. Over time, however, the response to the chronic hemodynamic overload becomes maladaptive, resulting in cardiac dilatation and heart failure.2 The murine TAC model was first validated by Rockman et al.1, and has since been extensively used as a valuable tool to mimic human cardiovascular diseases and elucidate fundamental signaling processes involved in the cardiac hypertrophic response and heart failure development. When compared to other experimental models of heart failure, such as complete occlusion of the left anterior descending (LAD) coronary artery, TAC provides a more reproducible model of cardiac hypertrophy and a more gradual time course in the development of heart failure. Here, we describe a step-by-step procedure to perform surgical TAC in mice. To determine the level of pressure overload produced by the aortic ligation, a high frequency Doppler probe is used to measure the ratio between blood flow velocities in the right and left carotid arteries.3, 4 With surgical survival rates of 80-90%, transverse aortic banding is an effective technique of inducing left ventricular hypertrophy and heart failure in mice.

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model to study mechanisms underlying cardiac hypertrophy and heart failure development. Here, we describe procedures to constrict the aorta to create a reproducible degree of cardiac hypertrophy in mice.

마우스의 가로 대동맥 수축

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart ...

생물학

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.

마우스의 심장 판막 질환의 종합 표현형 특성에 대한 심 초음파 접근 및 프로토콜

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 ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

마우스의 최소 침습 가로 대동맥 수축

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Echocardiographic and Histological Examination of Cardiac Morphology in the Mouse

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed in mice is high. Phenotypic characterization of these mouse models also requires the examination of cardiac function and morphology. Echocardiography and magnetic resonance imaging (MRI) are commonly used approaches to characterize cardiac function and morphology in mice. Echocardiographic and MRI equipment specialized for use in small rodents is&#160;expensive and requires a dedicated space. This protocol describes cardiac measurements in mice using a clinical echocardiographic system with a 15 MHz human vascular probe. Measurements are performed on anesthetized adult mice. At least three image sequences are recorded and analyzed for each animal in M-mode in the parasternal short-axis view. Afterwards, cardiac histological examination is performed, and cardiomyocyte diameters are determined on hematoxylin-eosin- or wheat germ agglutinin (WGA)-stained paraffin sections. Vessel density is determined morphometrically after Pecam-1 immunostaining. The protocol has been applied successfully to pharmacological studies and different genetic animal models under baseline conditions, as well as after experimental myocardial infarction by the permanent ligation of the left anterior descending coronary artery (LAD). In our experience, echocardiographic investigation is limited to anesthetized animals and is feasible in adult mice weighing at least 25 g.

Echocardiographic examination is frequently used in mice. Expensive high-resolution ultrasound devices have been developed for this purpose. This protocol describes an affordable echocardiographic procedure combined with histological morphometric analyses to determine cardiac morphology.

마우스의 심장 형태학의 echocardiographic 및 조직학 검사

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed ...

Echocardiographic Measurement of Right Ventricular Diastolic Parameters in Mouse

Diastolic dysfunction is a prominent feature of right ventricular (RV) remodeling associated with conditions of pressure overload. However, the RV diastolic function is rarely quantified in experimental studies. This might be due to technical difficulties in the visualization of the RV in the apical four-chamber view in rodents. Here we describe two positions facilitating the visualization of the apical four-chamber view in mice to assess the RV diastolic function.
The apical four-chamber view is enabled by tilting the mouse fixation platform to the left and caudally (LeCa) or to the right and cranially (RiCr). Both positions provide images of comparable quality. The results of the RV diastolic function obtained from two positions are not significantly different. Both positions are comparably easy to perform. This protocol can be incorporated into published protocols and enables detailed investigations of the RV function.

Here we describe and compare two positions for obtaining the apical four-chamber view in mice. These positions enable the quantification of the right ventricular function, provide comparable results, and can be used interchangeably.

마우스의 우심실 확장기 매개변수의 심초음파 측정

Diastolic dysfunction is a prominent feature of right ventricular (RV) remodeling associated with conditions of pressure overload. However, the RV ...

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 ...

A Modified Technique for Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of pressure overload in mouse models. The main challenge of this procedure is to clearly visualize the transverse aortic arch and precisely band the target vessel. Classical approaches perform a partial thoracotomy to expose the transverse aortic arch. However, it is an open-chest model that causes a rather large surgical trauma and requires a ventilator during the surgery. To prevent unnecessary trauma and simplify the operating procedure, the aortic arch is approached via the proximal proportion of the sternum, reaching and binding the target vessel using a small self-made retractor that contains a snare. This procedure can be conducted without entering the pleura cavity and does not need a ventilator or microsurgical operation, which leaves the mice with physiological breathing patterns, simplifies the procedure, and significantly reduces operation time. Due to the less invasive approach and less operation time, mice can undergo fewer stress reactions and recover rapidly.

The present protocol describes a modified and simplified technique with a minimally invasive transverse aortic constriction (TAC) procedure using a self-made retractor. This procedure can be conducted without a ventilator or microscope and introduces pressure overload, eventually leading to cardiac hypertrophy or heart failure.

생쥐의 횡방향 대동맥 수축에 대한 수정된 기술

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of ...