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RISS 인기검색어
- 검색키워드
- 저자 : Andrew Kohut (검색결과 4 건)
- 무료
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Comprehensive Echocardiographic Assessment of the Right Ventricle in Murine Models
Andrew Kohut,Nishi Patel,Harpreet Singh 한국심초음파학회 2016 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.24 No.3
Background: Non-invasive high-resolution echocardiography to evaluate cardiovascular function of small animals is increasingly being used due to availability of genetically engineered murine models. Even though guidelines and standard values for humans were revised by the American Society of Echocardiography, evaluations on murine models are not performed according to any standard protocols. These limitations are preventing translation of preclinical evaluations to clinical meaningful conclusions. We have assessed the right heart of two commonly used murine models according to standard clinical guidelines, and provided the practical guide and sample values for cardiac assessments. Methods: Right heart echocardiography evaluations of CD1 and C57BL/6 mice were performed under 1–3% isoflurane anesthesia using Vevo® 2100 Imaging System with a high-frequency (18–38 MHz) probe (VisualSonics MS400). We have provided a practical guide on how to image and assess the right heart of a mouse which is frequently used to evaluate development of right heart failure due to pulmonary hypertension. results: Our results show significant differences between CD1 and C57BL/6 mice. Right ventricle structural assessment showed significantly larger (p < 0.05) size, and pulmonary artery diameter in CD1 mice (n = 11) compared to C57BL/6 mice (n = 15). Right heart systolic and diastolic functions were similar for both strains. Conclusion: Our practical guide on how to image and assess the right heart of murine models provides the first comprehensive values which can be used for preclinical research studies using echocardiography. Additionally, our results indicate that there is a high variability between mouse species and experimental models should be carefully selected for cardiac evaluations.
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S. Jeffrey Yakish,Arvin Narula,Robert Foley,Andrew Kohut,Steven Kutalek 한국심초음파학회 2015 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.23 No.1
Background: Currently there is no noninvasive imaging modality used to risk stratify patients requiring lead extractions. Wereport the novel use of superior vena cava (SVC) echocardiography to identify lead fibrosis and complex cardiac implantableelectronic device (CIED) lead extraction. With an aging population and expanding indications for cardiac device implantation,the ability to deal with the complications associated with chronically implanted device has also increased. Methods: This was a retrospective analysis of Doppler echocardiography recorded in our outpatient Electrophysiology/DeviceClinic office over 6 months. Images from 109 consecutive patients were reviewed. Results: 62% (68/109) did not have a CIED and 38% (41/109) had a CIED. In patients without a CIED, 6% (4/68) displayedturbulent color flow by Doppler in the SVC, while 22% (9/41) of patients with a CIED displayed turbulent flow. Fisher’s exacttest found a statistically significant difference between the two groups (p value < 0.05). The CIED group was subdivided into 2groups based on device implant duration (< 2 years vs. ≥ 2 years). Of the CIED implanted for ≥ 2 years, 27% (9/33) hadturbulent flow in the SVC by Doppler, while no patients (0/8) with implant durations < 2 years demonstrated turbulent flow. Nine patients underwent subsequent lead extraction. A turbulent color pattern successfully identified all 3 patients that hadsignificant fibrosis in the SVC found during extraction. Conclusion: Our data suggests that assessing turbulent flow using color Doppler in the SVC may be a valuable noninvasivescreening tool prior to lead extraction in predicting complex procedures.
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Ankur Chaudhury,Austin Wanek,Devasena Ponnalagu,Harpreet Singh,Andrew Kohut 한국심초음파학회 2021 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.29 No.2
BACKGROUND: It is difficult to simulate the abnormal myocardial strain patterns caused by ischemic coronary artery disease (CAD) which are a precursor to heart failure (HF) within an animal model. Simulation of these strain changes could contribute to better understanding of the early formative stages of HF. This is especially important in investigating the poorly understood pathogenesis of heart failure with preserved ejection fraction (HFpEF). Here, we discuss delivery of high intensity focused ultrasound (HIFU) in a murine model to alter left ventricular (LV) regional longitudinal strain (RLS), and use of speckle tracking echocardiography to detect these changes. METHODS: HIFU pulses (pressure amplitude 1.7 MPa) were generated by amplifying a sinusoidal waveform from a function generator into a piezoelectric transducer. These pulses were then directed extracorporeally towards the anterior LV surface of C57BI6 mice during three time periods (early, mid, and late diastole). Speckle tracking echocardiography was then used to quantify changes in RLS within six segments of the LV. RESULTS: We observed an increase in LV RLS with acoustic augmentation during all three time periods. This augmentation was most prominent near the anterior apical region in early diastole and near the posterior basilar region during late diastole. CONCLUSIONS: Our findings demonstrate the application of HIFU to non-invasively induce changes in RLS within a murine model. Our results also reflect the capability of speckle tracking echocardiography to analyze and quantify these changes. These findings represent the first demonstration of ultrasound-induced augmentation in LV RLS within a small animal model.
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