우리는 박사 코리 레이놀즈이 프로젝트와 시설에 친절한 액세스할 수있는 그들의 전문적인 도움 BCM 마우스 Phenotyping 코어를 감사하고 싶습니다. XHTW 의료 연구에 WM 켁 재단 고유 영 학자이며, 또한 NIH / NHLBI 보조금 R01 - R01 - HL089598 및 HL091947, 그리고 근육질 영양 장애 협회 부여 # 69238에 의해 지원됩니다. 이 작품도 마음에 CaMKII 시그널링을위한 재단 Leducq 동맹에 의해 부분적으로 지원됩니다.

1. 이미징 연구에 대비하여 쥐 <ol><li> 이전 이미징 연구, 유도 챔버에서 마우스 (2 % isoflurane 0.5 L / 분 섞인 백퍼센트 O 2) 마취. 연산자의 안전을 위해 폐기물 가스를 필터링해야합니다. 유도 챔버에서 동물을 제거하고 neckline 중순 가슴 수준으로 모피를 면도하는 헤어 가위를 사용합니다. 그런 다음 제모 크림과 함께 남아있는 체모를 제거합니다. 이 준비는 생쥐의 잠재 바람직하지 않은 스트레스 반응을 최소화하기 위해 이전 이미징 연구에 하루 수행할 수 있습니다. </li><li> (겔 작은 주걱으로 각막을 접촉하지 않도록) 공막엔 건조 방지하기 위해 양쪽 눈 젤 duralube 적용합니다. 임베디드 ECG와 난방 패드 위에 부정사 위치에 마우스를 anesthetized 플레이스하면 체온을 유지하기 위해 연결됩니다. </li><li> 프로 시저를 통해 정상 상태 진정 작용 수준 (0.5 L / 분 백퍼센트 O 2 혼합 isoflurane 1.0 % 1.5 %) 유지하기 위해 마취 시스템에 연결된 코 콘 안에 주둥이를 놓습니다. 진정 작용을 확인 발가락이나 꼬리 핀치를 수행합니다. 필요한 경우, 마취의 수준이 450의 목표 심장 박동수 ± 분당 50 비트 (BPM)을 구하는 조정할 수 있습니다. </li><li> 부드럽게 지속적으로 모니터하고 가열 패드를 통해 체온을 조절하기 위해 직장 탐사선 (윤활 이후) 넣습니다. 좁은 범위 내에서 체온을 유지하는 것이 중요하다 (37.0 ° C ± 0.5 ° C)로 온도와 심장 박동에도 온건한 변화가 생쥐의 심장 기능에 영향을 미칩니다. </li><li> 푸르 포스와 테이프 그들 ECG 전극으로하는 전극 젤을 적용합니다. </li></ol> 2. 심장의 평가 수축기 기능 <ol><li> 이 절차를 시작하려면, 마음을 overlying 주로 지역, 가슴에 preheated 초음파 젤의 레이어를 적용합니다. 젤는 대략적인 체온을 따뜻하게해야합니다. 감기 젤의 볼륨 빠르게 체온 손실의 비율에 추가할 수 있습니다. 초음파 영상을 방해할 수있는 겔에서 공기 방울을 피하십시오. </li><li> 약간의 각도에 따라 약간 위쪽으로 위치 (머리까지)에 마우스를 고정. micromanipulator 사용하여 프로브와 심장 사이에 90 ° 각도로 초음파 프로브를 고정. </li><li> 짧은 축 echocardiographic 측정을 시작하려면 parasternally 흉부에 프로브를 낮춥니다. 이 신호를 왜곡하므로, 직접 가슴을 통해 또는 피부에 프로브를 삽입하지 마십시오. </li><li> 첫째, 우리는 parasternal 짧은 축을 따라보기를 얻기 위해 2 차원 (2D) 영상 ( &#39;B - 모드&#39;) 수행합니다. 동물의 심장의 크기에 따라 완벽한 이미지를 얻기 위해 프로브의보기 영역을 조정합니다. </li><li> 이 오리 엔테이션에 적절한 이미지가 좌심실과 오른쪽 심실 벽의 약간의 부분을 포함합니다. 화살표 (비디오 참조) anterolateral 및 posteromedial 젖꼭지 근육, LV의 뒷부분과 앞쪽에 벽, 심실 septal 벽, 오른쪽 심실 벽의 약간의 부분을 나타냅니다. 이러한 측정을하는 동안 잠재적인 벽 운동 이상 (예 : hypokinesia, akinasia, asynchrony) 또는 동맥류에 특별한 관심을 지불합니다. </li><li> 다음, 우리는 심장 크기와 수축성의 좋은 측정을 얻기 위해, 1 차원 (1D)보기를 제공 M - 모드 echocardiography를 사용합니다. 스토어 수축기 왼쪽 심실 기능의 매개 변수를 나중에 평가에 대한 이미지를 인수했다. </li></ol> 3. 마음의 Diastolic 기능을 평가 <ol><li> 아직 parasternal 짧은 축을 보는 동안, 우리는 심근 운동의 속도를 측정하는 조직 도플러 영상 (TDI)을 수행할 수 있습니다. 관심 지역은 레이디얼 축 평가 사후 왼쪽 심실 벽을 포함하도록 표시됩니다. 얻은 파형은 diastolic 기능을 평가하는 푸르 피크스을 갖습니다 IVRT, E &#39;, A&#39;, 그리고 IVCT 있습니다. s &#39;이 (가) 수축기 속도를 나타냅니다. (그림 3B)이 매개 변수는 대표적인 결과 섹션의 뒷부분에서 설명합니다. </li><li> 펄스 파 도플러 (PWD)는 심근 조직의 특정 깊이에서 작은 영역 내에 혈류 속도를 측정하는 데 사용할 수 있습니다. 이미지 횡단 승모판 흐름 패턴을하려면 Trendelenburg 위치에서 뒤로 동물을 기울. , 위쪽 프로브 마음의 꼭대기와 직교되어 같은 프로브를 기울이기. </li><li> 이제 승모판의 움직임을 느리게합니다 300-350 BPM에 심장 박동을 낮출 isoflurane 수준을 향상시킬 수 있습니다. 비교 연구, 동물 사이에 유사한 심장 속도를 유지하는 것이 중요합니다. </li><li> 밸브를 통해 흐름을 측정하는 기준점으로 승모판의 움직임을 시각화. 승모판의 끝에 샘플 볼륨을 넣으십시오. </li><li> PWD를 사용하여 승모판 전체 흐름 패턴을 측정합니다. 두 개의 파도가 특질상 볼 수 있으며, 뇌실의 수동 작성 (초기 [E] 웨이브)를 대표하고,심방 수축기 (심방 [A] 파도)에 적극적으로 충전과 일치 하나. 건강한 마음에서 E - 파 속도는 파도 (그림 3C)의보다 약간 큽니다. </li><li> 모든 측정이 완료되면, 전극 젤 (부드럽게 표준 거즈 패드로 닦아로)와 동물의 억제를 제거합니다. 억제 동물이 똑바로 위치에 온수 ECG 패드 정상 회복 및 마취을 해제하도록 허용합니다. 마우스가 깨어난다 때, 그 케이지로 돌아갑니다. </li></ol> 4. 대표 Transthoracic Echocardiography 결과 비침 투 echocardiographic 연구 왼쪽 심실 형태학 및 심장 질병의 murine 모델의 기능을 평가하는 데 사용할 수 있습니다. 4,5이 방법이 널리 사용 및 intracardiac 압력 볼륨 루프 measurements.8로 LV 기능을 평가하기 위해 터미널 절차에 대한 대안을 제공합니다 또는 전 생체내 근무 심장 모델. transthoracic M - 모드 echocardiography에 의해 LV 챔버 크기 9 평가는 비정상 LV 챔버 확대 또는 심장 질환의 다양한 모델로 증가 벽 두께의 검출을 허용합니다. 펄스 파 도플러와 함께 따라서 5, transthoracic echocardiography는, , 수축기 및 생쥐의 diastolic 심장 기능의 비침습 평가를위한 종합 애비뉴 것으로 간주됩니다. <img src="/files/ftp_upload/1738/1738fig1.jpg" alt="그림 1" /> 그림 1. Echocardiography 및 도플러 영상에 대한 VIVO 마이크로 이미징 시스템에서 Vevo 770 고해상도의 개요. (A) 우리는 생리 감시 장치, 심전도 보드와 RMV 30mHz 스캔 머리와 VisualSonics 통합 레일 시스템을 사용합니다. (B) 마우스 위치 및 통합 ECG 전극 (골드 색상)으로 가열 보드에 제대로 구속됩니다. 사지는 ECG 전극으로 녹화됩니다. (CD) 펄스 파 도플러에 대해 적절한 각도를 보여주는 사진은 프로토콜의 제 4에 설명되어있는 diastolic 기능 측정을 취득하는 데 사용됩니다. 수축기 기능 측정을위한 프로브 방향은 비디오 프로토콜에 표시하고 있습니다. <img src="/files/ftp_upload/1738/1738fig2.jpg" alt="그림 2" /> 그림 2. 대표 2D의 Echocardiography 이미지 (B - 모드). 왼쪽 심실 앞쪽에 (AW)과 사후 (PW) 벽, 심실 septal 벽 (SW) 및 측면 벽 (LW)를 표시 (A) 파라 - 흉골 짧은 축 볼 수 있습니다. 왼쪽 심실 루멘의 직경은 왼쪽 심실 내경 (LVID)로 측정할 수 있습니다. 별표 posteromedial 젖꼭지 근육을 나타냅니다. E / 최대 판매율의 결정에 대한 승모판 통해 보는 공간 (B) 꼭대기의 안경 챔버 볼 수 있습니다. MVAL, 승모판 앞쪽에 전단지, MVPL, 승모판 후부 전단지, RV, 우심실, LV는 뇌실을 떠났다. <img src="/files/ftp_upload/1738/1738fig3.jpg" alt="그림 3" /> 그림 3. 취득 및 Echocardiography 및 도플러 데이터 부량.이 그림은 그림 2에 표시되는 2D echocardiography 이미지에 해당하는 취득 데이터의 대표 이미지가 포함되어 있습니다. (A) M - 모드는 최종 수축기 (ESD) 및 최종 diastolic 직경 (EDD)을 나타내는 라인 추적. LVAWD / S, 왼쪽 심실 앞쪽에 벽 두께 (심장 확장 / 수축기); LVPWD / S는 심실 후부 벽 두께 (심장 확장 / 수축기)을 떠났다. (B) LV 후부 벽 조직 도플러 영상에 대한 대표 tracings. IVRT, isovolumic 휴식 시간, IVCT, isovolumic 수축 시간. E &#39;의 파도는 LV의 작성 초기 diastolic 동안 승모판 고리의 움직임에 해당하고,&#39;파도 늦게 LV의 작성 중에 수축기 심방에서 유래. s &#39;이 (가) 수축기 속도를 나타냅니다. (C) 승모판 전단지 팁의 펄스 웨이브 도플러 녹음 일찍 diastolic 속도 (E), diastolic 수축 늦게 diastolic 속도 (A) 및 E / A 비율을 얻을 수있는 승모판 유입 속도 패턴을 제공합니다. IVRT 또한 diastolic 기능과 충전 압력을 특성화하는 유용한 변수입니다. 동부 표준시은 배출 시간을 나타냅니다.

<ol>
	<li>Zhang, T. M. a. i. e. r., S, L., Dalton, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+deltaC+isoform+of+CaMKII+is+activated+in+cardiac+hypertrophy+and+induces+dilated+cardiomyopathy+and+heart+failure.">The deltaC isoform of CaMKII is activated in cardiac hypertrophy and induces dilated cardiomyopathy and heart failure.</a> Circ Res. 92 (8), 912-912 (2003).</li><li>Srivastava, D., Thomas, T., Lin, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+cardiac+mesodermal+and+neural+crest+development+by+the+bHLH+transcription+factor,+dHAND.">Regulation of cardiac mesodermal and neural crest development by the bHLH transcription factor, dHAND.</a> Nat Genet. 16 (2), 154-154 (1997).</li><li>Sood, S., Chelu, M. G., van Oort, 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=Intracellular+calcium+leak+due+to+FKBP12.6+deficiency+in+mice+facilitates+the+inducibility+of+atrial+fibrillation.">Intracellular calcium leak due to FKBP12.6 deficiency in mice facilitates the inducibility of atrial fibrillation.</a> Heart Rhythm. 5 (7), 1047-1047 (2008).</li><li>Gardin, J. M., Siri, F. M., Kitsis, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+assessment+of+left+ventricular+mass+and+systolic+function+in+mice.">Echocardiographic assessment of left ventricular mass and systolic function in mice.</a> Circ Res. 76 (5), 907-907 (1995).</li><li>Tanaka, N., Dalton, N., Mao, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transthoracic+echocardiography+in+models+of+cardiac+disease+in+the+mouse.">Transthoracic echocardiography in models of cardiac disease in the mouse.</a> Circulation. 94 (5), 1109-1109 (1996).</li><li>Patten, R. D., Aronovitz, M. J., Bridgman, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+pulse+wave+and+color+flow+Doppler+echocardiography+in+mouse+models+of+human+disease.">Use of pulse wave and color flow Doppler echocardiography in mouse models of human disease.</a> J Am Soc Echocardiogr. 15 (7), 708-708 (2002).</li><li>Garcia-Fernandez, M. A., Azevedo, J., Moreno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+Left+Ventricular+Diastolic+Dysfunction+Evaluated+by+Pulsed-Tissue+Doppler+Echocardiography.">Regional Left Ventricular Diastolic Dysfunction Evaluated by Pulsed-Tissue Doppler Echocardiography.</a> Echocardiography. 16 (5), 491-491 (1999).</li><li>Pacher, P., Nagayama, T., Mukhopadhyay, P. <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+cardiac+function+using+pressure-volume+conductance+catheter+technique+in+mice+and+rats.">Measurement of cardiac function using pressure-volume conductance catheter technique in mice and rats.</a> Nat Protoc. 3 (9), 1422-1422 (2008).</li><li>Larsen, T. S., Belke, D. D., Sas, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Pflugers Arch. 437 (6), 979-979 (1999).</li><li>Roth, D. M., Swaney, J. S., Dalton, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+anesthesia+on+cardiac+function+during+echocardiography+in+mice.">Impact of anesthesia on cardiac function during echocardiography in mice.</a> Am J Physiol Heart Circ Physiol. 282 (6), H2134-H2134 (2002).</li></ol>

M - 모드 echocardiography를 사용할 때 마우스의 다른 그룹 또는 genotypes 사이의 비교를 용이하게하기 위해 마우스의 코호트 내에서 마취 수준, 10 체온과 심장 박동을 표준화하는 것이 중요합니다. diastolic 기능 PWD의 평가, 심장 요금은 murine 마음의 diastolic 속성을 평가하기 위해서는 인하되어야합니다. 동물의 가장 중요한 기능이 밀접하게 hemodynamic 실패와 죽음을 방지하기 위해 준수해야합니다. 한편, 분당 400 비트 이하 M - 모델 echocardiography, 심장 속도를 사용하여 수축기 기능 측정을위한 최종 diastolic 직경이 증가 LV의 작성에 의한 증가가 발생할 수 있습니다.

* 필수 소프트웨어는 B - 모드 응용 프로그램, 펄스 파 도플러 응용 프로그램, 그리고 심장 혈관 분석 도구 패키지를 포함 Vevo 소프트웨어입니다.

transthoracic echocardiography in mice

최근에는 murine 모델은 유전자 발현의 변화로 인한 심장 장애의 분자 메커니즘을 연구하기위한 중요한 수단이되었습니다. 유전자 변형과 유전자 타겟팅 방법은 변경된 심장 크기와 기능을 가진 생쥐를 생성하는 데 사용할 수 있습니다<sup&gt; 1-3</sup&gt; 그 결과로,<em&gt; 생체내에</em&gt; 기술들은 심장병 표현형을 평가하기 위해 필요합니다. Transthoracic echocardiography, 펄스 파 도플러 (PWD) 및 조직 도플러 영상 (TDI)은 마우스 심장의 차원 측정을 제공하고 심장 수축기 및 diastolic 성능의 정도를 계량하는 데 사용할 수 있습니다. M - 모드 에코는 심장 크기와 수축성의 부량 사용되는 반면, 2 차원 영상은 비정상적인 신체 구조 또는 좌심실의 움직임을 감지하는 데 사용됩니다.<sup&gt; 4,5</sup&gt; 또한, PWD는 난류의 지역화된 속도를 계량하는 데 사용됩니다<sup&gt; 6</sup&gt; 반면 TDI는 심근 운동의 속도를 측정하는 데 사용됩니다.<sup&gt; 7</sup&gt; 따라서, transthoracic echocardiography는 생쥐에서 심장 기능의 비침 투 평가에 대한 포괄적인 방법을 제공합니다.

Watch this Scientific Journal Video about Transthoracic Echocardiography in Mice at JoVE.com

Transthoracic Echocardiography in Mice

Transthoracic echocardiography는 생쥐에서 심장 기능의 평가에 대한 비침 투 방법을 제공합니다. 초음파 및 도플러 영상 modalities의 조합이 심장과 함께 심장 수축기 및 diastolic 성능 평가를 제공 intracardiac 혈액 흐름의 차원 측정을 얻을하는 데 사용할 수 있습니다.

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 ...

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61.5K 조회수.  Baylor College of Medicine (BCM). Transthoracic echocardiography는 생쥐에서 심장 기능의 평가에 대한 비침 투 방법을 제공합니다. 초음파 및 도플러 영상 modalities의 조합이 심장과 함께 심장 수축기 및 diastolic 성능 평가를 제공 intracardiac 혈액 흐름의 차원 측정을 얻을하는 데 사용할 수 있습니다.

비디오: Transthoracic Echocardiography in Mice

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  ...

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Murine Fetal Echocardiography

Transgenic mice displaying abnormalities in cardiac development and function represent a powerful tool for the understanding the molecular mechanisms underlying both normal cardiovascular function and the pathophysiological basis of human cardiovascular disease. Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development 1-3. In order to study the role of genetic or pharmacologic alterations in the early development of cardiac function, ultrasound imaging of the live fetus has become an important tool for early recognition of abnormalities and longitudinal follow-up. Noninvasive ultrasound imaging is an ideal method for detecting and studying congenital malformations and the impact on cardiac function prior to death 4. It allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies 5,6. Until recently, imaging of fetal mouse hearts frequently involved invasive methods. The fetus had to be sacrificed to perform magnetic resonance microscopy and electron microscopy or surgically delivered for transillumination microscopy. An application of high-frequency probes with conventional 2-D and pulsed-wave Doppler imaging has been shown to provide measurements of cardiac contraction and heart rates during embryonic development with databases of normal developmental changes now available 6-10. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. High-frequency ultrasound imaging of the fetus has improved 2-D resolution and can provide excellent information on the early development of cardiac structures 11.

Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.

손쥐 태아 Echocardiography

Transgenic mice displaying abnormalities in  cardiac development and function represent a powerful tool for the understanding  the molecular mechanisms ...

In utero Measurement of Heart Rate in Mouse by Noninvasive M-mode Echocardiography

Congenital heart disease (CHD) is the most frequent noninfectious cause of death at birth. The incidence of CHD ranges from 4 to 50/1,000 births (Disease and injury regional estimates, World Health Organization, 2004). Surgeries that often compromise the quality of life are required to correct heart defects, reminding us of the importance of finding the causes of CHD. Mutant mouse models and live imaging technology have become essential tools to study the etiology of this disease. Although advanced methods allow live imaging of abnormal hearts in embryos, the physiological and hemodynamic states of the latter are often compromised due to surgical and/or lengthy procedures. Noninvasive ultrasound imaging, however, can be used without surgically exposing the embryos, thereby maintaining their physiology. Herein, we use simple M-mode ultrasound to assess heart rates of embryos at E18.5 in utero. The detection of abnormal heart rates is indeed a good indicator of dysfunction of the heart and thus constitutes a first step in the identification of developmental defects that may lead to heart failure.

In utero Measurement of Heart Rate in Mouse by Noninvasive M-mode Echocardiography

Ultra-high frequency ultrasound is a powerful live imaging tool to examine cardiac abnormalities in small animals. Its noninvasiveness allows maintaining the physiologic state of embryos. Herein, we show the use of M-mode ultrasound to measure the heart rates of embryos at E18.5 in utero.

비 침습 M-모드 초음파 심장 검진 법에 의한 마우스의 심장 박동의 자궁 측정

Congenital heart disease (CHD) is the most frequent noninfectious cause of death at birth. The incidence of CHD ranges from 4 to 50/1,000 births (Disease ...

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, ...

Ultrasound-guided Transthoracic Intramyocardial Injection in Mice

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. Experiments involving myocardial injection are currently performed by direct surgical access through a thoracotomy. While convenient when performed at the time of another experimental manipulation such as coronary artery ligation, the need for an invasive procedure for intramyocardial delivery limits potential experimental designs. With ever improving ultrasound resolution and advanced noninvasive imaging modalities, it is now feasible to routinely perform ultrasound-guided, percutaneous intramyocardial injection. This modality efficiently and reliably delivers agents to a targeted region of myocardium. Advantages of this technique include the avoidance of surgical morbidity, the facility to target regions of myocardium selectively under ultrasound guidance, and the opportunity to deliver injectate to the myocardium at multiple, predetermined time intervals. With practiced technique, complications from intramyocardial injection are rare, and mice quickly return to normal activity on recovery from anesthetic. Following the steps outlined in this protocol, the operator with basic echocardiography experience can quickly become competent in this versatile, minimally invasive technique.

Echocardiography-guided percutaneous intramyocardial injection represents an efficient, reliable, and targetable modality for the delivery of gene transfer agents or cells into the murine heart. Following the steps outlined in this protocol, the operator can quickly become competent in this versatile, minimally invasive technique.

마우스의 초음파 유도 경 흉부 심근 내 주입

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the examiners&#39; expertise. Speckle tracking Echocardiography (STE) is a promising but technically challenging method that can be used to quantitatively assess regional and global systolic and diastolic myocardial performance. Myocardial strain and strain rate can be measured in all three dimensions&#160;&#8212; radial, circumferential, longitudinal &#8212; of myocardial deformation. Standard cross-sectional two-dimensional B-mode images are recorded and subsequently postprocessed by automated continuous frame-by-frame tracking and motion analysis of speckles within the myocardium. Images are recorded as digital loops and synchronized to a 3-lead EKG for timing purposes. Longitudinal deformation is assessed in the apical 4-, 3-, and 2-chamber views. Circumferential and radial deformation are measured in the parasternal short axis plane.
Optimal image quality and accurate tissue tracking are paramount for the correct determination of myocardial performance parameters. Utilizing transthoracic STE in a healthy volunteer, the present article is a detailed outline of the essential steps and potential pitfalls of quantitative echocardiographic myocardial deformation analysis.

Speckle tracking echocardiography is an emerging diagnostic imaging technique for the quantitative assessment of global and regional myocardial performance. Standard view echocardiographic motion images are recorded and deformation parameters are subsequently measured by automated continuous frame-by-frame tracking and motion analysis of speckles within the B-mode images of the myocardium.

좌심실 심근 변형의 정량적 평가를위한 흉부 얼룩 추적 심 초음파

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the ...

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic pressure through echocardiography, as well as to obtain measurements of the Aorta and PA diameter in mice.
Mice older than 10 d of age can be analyzed using the present technique. The technique is composed of 3 main steps: set-up, image acquisition, and image analysis. The set-up step consists of getting the mouse anesthetized with 1% isoflurane, shaving it, and taping it in a supine position to a heated EKG board where the image acquisition will take place. The image acquisition step consists of learning to identify the cardiac structures and obtaining all the required images with its correspondent probe and axis in order to be able to calculate volumes and diameters. The image analysis step consists of measuring the previously acquired images with the aid of computer software.
Advantages of the proposed technique include a fast (15 min) procedure that would allow the researcher to evaluate interventions in a non-invasive, non-terminal approach and therefore follow the same mouse over time; each mouse can be used as its own control. This fact plus having the same operator perform all the acquisition and analysis for the entire experiment minimizes the limitation of operator-dependency. The present methodology is useful for mouse researchers in cardiovascular and pulmonary medicine.

The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary function.

왼쪽 아트리움, 대동맥과 폐동맥의 쥐 심 초음파

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic ...

2D and 3D Echocardiography in the Axolotl (Ambystoma Mexicanum)

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model species such as zebrafish and salamanders that are capable of intrinsic heart regeneration hold promise for future regenerative therapies for human patients. To evaluate the outcome of cardioregenerative experiments it is imperative that heart function can be monitored. The axolotl salamander (A. mexicanum) represents a well-established model species in regenerative biology attaining sizes that allows for evaluation of cardiac function. The purpose of this protocol is to establish methods to reproducibly measure cardiac function in the axolotl using echocardiography. The application of different anesthetics (benzocaine, MS-222, and propofol) is demonstrated, and the acquisition of two-dimensional (2D) echocardiographic data in both anesthetized and unanesthetized axolotls is described. 2D echocardiography of the three-dimensional (3D) heart can suffer from imprecision and subjectivity of measurements, and to alleviate this phenomenon a solid method, namely intra/inter-operator/observer analysis, to measure and minimize this bias is demonstrated. Finally, a method to acquire 3D echocardiographic data of the beating axolotl heart at a very high spatiotemporal resolution and with pronounced blood-to-tissue contrast is described. Overall, this protocol should provide the necessary methods to evaluate cardiac function and model anatomy, and flow dynamics in the axolotl using ultrasound imaging with applications in both regenerative biology and general physiological experiments.

2D and 3D Echocardiography in the Axolotl Ambystoma Mexicanum

Here we present echocardiography protocols for two-dimensional and three-dimensional image acquisition of the beating heart of the axolotl salamander (Ambystoma mexicanum), a model species in heart regeneration. These methods allow for longitudinal evaluation of cardiac function at a high spatiotemporal resolution.

Axolotl (Ambystoma Mexicanum)에서 2 차원 및 3 차원 심장 초음파 검사

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model ...

Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or excision. Many of these nodules are identified and excised via minimally invasive thoracic surgery; however, subcentimeter and subsolid nodules are frequently difficult to identify intra-operatively. This can be mitigated by the use of electromagnetic transthoracic needle localization. This protocol delineates the step-by-step process of electromagnetic localization from the pre-operative period to the postoperative period and is an adaptation of the electromagnetically guided percutaneous biopsy previously described by Arias et al. Pre-operative steps include obtaining a same day CT followed by the generation of a three-dimensional virtual map of the lung. From this map, the target lesion(s) and an entry site are chosen. In the operating room, the virtual reconstruction of the lung is then calibrated with the patient and the electromagnetic navigation platform. The patient is then sedated, intubated, and placed in the lateral decubitus position. Using a sterile technique and visualization from multiple views, the needle is inserted into the chest wall at the prechosen skin entry site and driven down to the target lesion. Dye is then injected into the lesion and, then, continuously during needle withdrawal, creating a tract for visualization intra-operatively. This method has many potential benefits when compared to the CT-guided localization, including a decreased radiation exposure and decreased time between the dye injection and the surgery. Dye diffusion from the pathway occurs over time, thereby limiting intra-operative nodule identification. By decreasing the time to surgery, there is a decrease in wait time for the patient, and less time for dye diffusion to occur, resulting in an improvement in nodule localization. When compared to electromagnetic bronchoscopy, airway architecture is no longer a limitation as the target nodule is accessed via a transparenchymal approach. Details of this procedure are described in a step-by-step fashion.

Presented here is a protocol for lung nodule localization using dye marking via electromagnetically navigated transthoracic needle access. The technique described here can be accomplished in the peri-operative period to optimize nodule localization and to successful resection when performing minimally invasive thoracic surgery.