NHLBI R01 HL073087 כדי CKS.

הנתונים מתח המבוססת על מדידת רבב באמצעות אלגוריתם מעקב הצופה יחסית פחות תלויים כמו רוב הניתוח מתבצע על ידי התוכנה. עם זאת הצופה צריך להיות זהיר במהלך מעקב של הדיירים epicardium ו endocardium של B-mode סרטים אשר תלוי יותר ניסיון. יתר על כן, M-mode ניתוח ומדידה של פרופילי מהירות הוא גם משקיף מינימלי תלוי. עם זאת, במדידה של עליית לחץ ומדידה של פעמים, הצופה צריך להיעשות בזהירות רבה מאוד במהלך המדידות כי הלחץ תלוי ישירות עם הריבוע של מהירות שיא כפי שבאה לידי ביטוי על ידי נוסחה של ברנולי בו אפילו כמות קטנה של טעות המדידה יכולה לייצר אפקט בריבוע על שגיאה הכולל במדידה של DP / dt. יתר על כן, פתח regurgitant אינו בהכרח קבוע לאורך כל התכווצות, וזו עלולה להשפיע על הערכת חומרת regurgitant. מינונים גבוהים יותר של הרדמה עלול לגרום לירידה הדרמטית של קיצור השבר הפרמטרים המשפיעים על תפקודי אחרים. לכן, השימוש הסטנדרטי של הרגעה חשוב לתוצאה טובה יותר. רוב הפרמטרים ניתן למדוד באמצעות שיטות אחרות, למשל, תיוג MRI יכולים למדוד זנים 2D and 3D. עם זאת, אקו הוא יותר ידידותי למשתמש.

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<tbody>
<tr>
<td>Material Name</td>
<td>Type</td>
<td>Company</td>
<td>Catalogue Number</td>
</tr>
<tr>
<td>Vevo2100</td>
<td>&nbsp;</td>
<td>VisualSonics, Inc., Canada</td>
<td>SN2100-0032</td>
</tr>
<tr>
<td>Ventilation device</td>
<td>&nbsp;</td>
<td>Harvard Apparatus, MA</td>
<td>n/a</td>
</tr>
<tr>
<td><a href="http://www.adinstruments.com/products/software/research/LabChart-Software/" target="_blank">PC Powerlab software</a></td>
<td>&nbsp;</td>
<td><a href="http://www.adinstruments.com/" target="_blank">AD Instruments</a></td>
<td>n/a</td>
</tr>
<tr>
<td>Isoflurane</td>
<td>&nbsp;</td>
<td>VEDCO, Inc., MO</td>
<td>5260-04-12</td>
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<tr>
<td>Aquasonic gel 100</td>
<td>&nbsp;</td>
<td>Parker Lab. Inc., NJ</td>
<td>01-02</td>
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high-frequency high-resolution echocardiography: first evidence on non-invasive repeated measure of myocardial strain, contractility, and mitral regurgitation in the ischemia-reperfused murine heart

איסכמיה reperfusion (IR) בוצע ניתוח בלב Murine אשר היו נתונים אז הדמיה חוזרות כדי לעקוב אחר השינויים בפרמטרים הזמני תפקודית של משמעות קלינית מפתח. דו מימדי סרטים נרכשו בקצב מסגרת גבוהה (8 kHz) ו נוצלו להעריך באיכות גבוהה מתח שריר הלב. שני מימדי elastograms (תמונות זן), כמו גם פרופילים זן, היו דמיינו. תוצאות היו חזקים כמותית להערכת IR-Induced שינויים אירועי לב כולל התכווצות (LV) שמאל חדרית, הרפיה LV שלבי isovolumetric של שני לבבות לפעום מראש IR ו-IR הודעה בעכברים ללא פגע. בנוסף, נפגעת במגזר מבחינת תנועה קיר עיוות אנטומי של שריר הלב infarcted היו דמיינו. Elastograms הצליחו באופן ייחודי כדי לספק מידע על הפרמטרים הבאים בנוסף מדדים פיזיולוגיים תקן שידוע כי הם יושפעו אוטם שריר הלב ב העכבר: קוטר פנימי של פתח שסתום אבי העורקים ואת מיטרלי, פתח regurgitant יעיל, מתח שריר הלב (כמו גם היקפיים כמו רדיאלי), מערבולת בדפוס זרימת הדם כפי שחשף את הסרטים דופלר צבע ופרופילים מהירות, asynchrony ב LV במגזר, ושינויים באורך ואת הכיוון של וקטורים הוכחת תנועה הקיר איטי יותר סימטרית. עבודה זו שמה דגש על הפגנה החזותי של כמה ניתוחים כאלה מבוצעים.

Watch this Scientific Journal Video about High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

תדירות גבוהה אולטרסאונד דופלר היא טכנולוגיה חדשנית להערכת תפקוד שריר הלב באזור. עבודה זו מציגה את העדות הראשונה הוכחת הישימות של פלטפורמה זו הדמיה תכליתי עבור למדוד את חוזרות ונשנות של מתח שריר הלב, dp / dt, ו regurgitation צניפי בלב אדום (IR) איסכמיה reperfused Murine.

בתדירות גבוהה ברזולוציה גבוהה אקו: העדות הראשונה על מדוד לא פולשני חוזרות ונשנות של הזנים Contractility שריר הלב, ו regurgitation צניפי בלב איסכמיה reperfused Murine

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

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Medicine

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

23.9K Views.  The Ohio State University. תדירות גבוהה אולטרסאונד דופלר היא טכנולוגיה חדשנית להערכת תפקוד שריר הלב באזור. עבודה זו מציגה את העדות הראשונה הוכחת הישימות של פלטפורמה זו הדמיה תכליתי עבור למדוד את חוזרות ונשנות של מתח שריר הלב, dp / dt, ו regurgitation צניפי בלב אדום (IR) איסכמיה reperfused Murine.

Video: High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

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.

אקו Murine והדמיה אולטראסאונד

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

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

תהודה מגנטית נגזר מסננים הערכה שריר הלב באמצעות מעקב אחר תכונות

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

Myocardial Infarction and Functional Outcome Assessment in Pigs

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One important prerequisite is a good understanding of all safety and efficacy aspects obtained in a large animal model that validly reflect the human scenario of myocardial infarction (MI). Pigs are widely used in this regard since their cardiac size, hemodynamics, and coronary anatomy are close to that of humans. Here, we present an effective protocol for using the porcine MI model using a closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. This approach is based on 90 min of myocardial ischemia, inducing large left ventricle infarction of the anterior, septal and inferoseptal walls. Furthermore, we present protocols for various measures of outcome that provide a wide range of information on the heart, such as cardiac systolic and diastolic function, hemodynamics, coronary flow velocity, microvascular resistance, and infarct size. This protocol can be easily tailored to meet study specific requirements for the validation of novel cardioregenerative biologics at different stages (i.e. directly after the acute ischemic insult, in the subacute setting or even in the chronic MI once scar formation has been completed). This model therefore provides a useful translational tool to study MI, subsequent adverse remodeling, and the potential of novel cardioregenerative agents.

This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented.

אוטם שריר לב והערכת תוצאה תפקודית בחזירים

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

דגם של שריר הלב איסכמיה reperfusion הפגיעה Murine באמצעות קשירת של העורק השמאלי קדמי יורד

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

Murine Isolated Heart Model of Myocardial Stunning Associated with Cardioplegic Arrest

The following protocol is of use to evaluate impaired cardiac function or myocardial stunning following moderate ischemic insults. The technique is useful for modeling ischemic injury associated with numerous clinically relevant phenomenon including cardiac surgery with cardioplegic arrest and cardiopulmonary bypass, off-pump CABG, transplant, angina, brief ischemia, etc. The protocol presents a general method to model hypothermic hyperkalemic cardioplegic arrest and reperfusion in rodent hearts focusing on measurement of myocardial contractile function. In brief, a mouse heart is perfused in langendorff mode, instrumented with an intraventricular balloon, and baseline cardiac functional parameters are recorded. Following stabilization, the heart is then subject to brief infusion of a cardioprotective hypothermic cardioplegia solution to initiate diastolic arrest. Cardioplegia is delivered intermittently over 2 hr. The heart is then reperfused and warmed to normothermic temperatures and recovery of myocardial function is monitored. Use of this protocol results in reliable depressed cardiac contractile function free from gross myocardial tissue damage in rodents.

The goal of this protocol to assess myocardial stunning following ischemic cardioplegic arrest in rodents.

דגם לב מבודד עכברי של Associated מקסימה שריר הלב עם מעצר Cardioplegic

The following protocol is of use to evaluate impaired cardiac function or myocardial stunning following moderate ischemic insults. The technique is useful ...

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.

אקו Murine של השמאל אטריום, אבי העורקים, ו עורק הריאה

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

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts. The optical mapping system is assembled with dual high-speed complementary metal oxide semiconductor cameras and high magnification objective lenses, to detect the fluorescence of a voltage-sensitive dye and Ca2+ indicator. To focus on the assessment of murine atria, optical mapping is performed with an area of 2 mm &#215; 2 mm or 10 mm x 10 mm, with a 100 &#215; 100 resolution (20 &#181;m/pixel or 100 &#181;m/pixel) and sampling rate of up to 10 kHz (0.1 ms) at maximum. A 1-French size quadripolar electrode pacing catheter is placed into the right atrium through the superior vena cava avoiding any mechanical damage to the atrium, and pacing stimulation is delivered through the catheter. An electrophysiological study is performed with programmed stimulation including constant pacing, burst pacing, and up to triple extrastimuli pacing. Under a spontaneous or pacing rhythm, the optical mapping recorded the action potential duration, activation map, conduction velocity, and Ca2+ transient individually in the right and left atria. In addition, the programmed stimulation also determines the inducibility of atrial tachyarrhythmias. Precise activation mapping is performed to identify the propagation of the excitation in the atrium during an induced atrial tachyarrhythmia. Optical mapping with a specialized setting enables a thorough electrophysiological evaluation of the atrium in murine pathological models.

This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter.

אלקטרופיזיולוגיות להערכת אטריה מאתר עם מיפוי אופטי ברזולוציה גבוהה

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and ...

A Cryoinjury Model to Study Myocardial Infarction in the Mouse

The use of animal models is essential for developing new therapeutic strategies for acute coronary syndrome and its complications. In this article, we demonstrate a murine cryoinjury infarct model that generates precise infarct sizes with high reproducibility and replicability. In brief, after intubation and sternotomy of the animal, the heart is lifted from the thorax. The probe of a handheld liquid nitrogen delivery system is applied onto the myocardial wall to induce cryoinjury. Impaired ventricular function and electrical conduction can be monitored with echocardiography or optical mapping. Transmural myocardial remodeling of the infarcted area is characterized by collagen deposition and loss of cardiomyocytes. Compared to other models (e.g., LAD-ligation), this model utilizes a handheld liquid nitrogen delivery system to generate more uniform infarct sizes.

This article demonstrates a model to study cardiac remodeling after myocardial cryoinjury in mice.

מודל לפציעה בהקפאה לחקור אוטם שריר הלב בעכבר

The use of animal models is essential for developing new therapeutic strategies for acute coronary syndrome and its complications. In this article, we ...

An Image Guided Transapical Mitral Valve Leaflet Puncture Model of Controlled Volume Overload from Mitral Regurgitation in the Rat

Mitral regurgitation (MR) is a widely prevalent heart valve lesion, which causes cardiac remodeling and leads to congestive heart failure. Though the risks of uncorrected MR and its poor prognosis are known, the longitudinal changes in cardiac function, structure and remodeling are incompletely understood. This knowledge gap has limited our understanding of the optimal timing for MR correction, and the benefit that early versus late MR correction may have on the left ventricle. To investigate the molecular mechanisms that underlie left ventricular remodeling in the setting of MR, animal models are necessary. Traditionally, the aorto-caval fistula model has been used to induce volume overload, which differs from clinically relevant lesions such as MR. MR represents a low-pressure volume overload hemodynamic stressor, which requires animal models that mimic this condition. Herein, we describe a rodent model of severe MR in which the anterior leaflet of the rat mitral valve is perforated with a 23G needle, in a beating heart, with echocardiographic image guidance. The severity of MR is assessed and confirmed with echocardiography, and the reproducibility of the model is reported.&#160;&#160;

A rodent model of left heart volume overload from mitral regurgitation is reported. Mitral regurgitation of controlled severity is induced by advancing a needle of defined dimensions into the anterior leaflet of the mitral valve, in a beating heart, with ultrasound guidance.&#160;

תמונה מונחית Transapical צניפי העלון נקב מודל של נפח מבוקרת עומס יתר מ צניפי אי-ספיקת בעכברוש

Mitral regurgitation (MR) is a widely prevalent heart valve lesion, which causes cardiac remodeling and leads to congestive heart failure. Though the ...

Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography

Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ventricular (RV) function has strong diagnostic and prognostic power in various cardiovascular disorders. Due to its complex morphology and function, assessment of the RV by conventional two-dimensional echocardiography is limited: the everyday clinical practice usually relies on simple linear dimensions and functional measures. Three-dimensional (3D) echocardiography overcame these limitations by providing volumetric quantification of the RV free of geometrical assumptions. Here, we offer a step-by-step guide to obtain and analyze 3D echocardiographic data of the RV using the leading commercially available software. We will quantify 3D RV volumes and ejection fraction. Several technical aspects may help to improve the quality of RV acquisition and analysis as well, which we present in a practical manner. We review the current opportunities and the limiting factors of this method and also highlight the potential applications of 3D RV assessment in current clinical practice.

Here, we provide a step-by-step acquisition and analysis protocol for the 3D volumetric assessment of the right ventricle, mainly focusing on the practical aspects that maximize the feasibility of this technique.