976 resultados para Left-ventricular Relaxation


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Background: Monocytes are implicated in the initiation and progression of the atherosclerotic plaque contributing to plaque instability and rupture. Little is known about the role of the three phenotypically and functionally different monocyte subpopulations in determining ventricular remodelling following ST elevation myocardial infarction (STEMI). Mon1 are the ‘classical’ monocytes with inflammatory action, whilst Mon3 are considered reparative with fibroblast deposition ability. The function of the newly described Mon2 subset is yet to be fully described. Method: STEMI patients (n=196, mean age 62±13 years; 72% male) treated with percutaneous revascularization were recruited within the first 24 h post-infarction. Peripheral blood monocyte subpopulations were enumerated and characterised using flow cytometry after staining for CD14, CD16 and CCR2. Phenotypically, monocyte subpopulations are defined as: CD14++CD16-CCR2+ (Mon1), CD14++CD16+CCR2+ (Mon2) and CD14+CD16++CCR2- (Mon3) cells. Transthoracic 2D echocardiography was performed within 7 days and at 6 months post infarct to assess ventricular volumes, mass, systolic, and diastolic functions as well as strain and strain rate. Results: Using linear regression analysis higher counts for Mon1, and lower counts for Mon2 and Mon3 were significantly associated with the baseline left ventricular ejection fraction (LVEF) within 7 days post infarct (table 1). At 6 months post STEMI lower counts of Mon2 remained positively associated with a decrease in LVEF at completion of remodelling (p=0.002). Conclusion: Peripheral monocytes of all three subsets correlate with LVEF after a myocardial infarction. High counts of the inflammatory Mon1 are associated with the reduced baseline ejection fraction post infarction. After remodelling, the convalescent ejection fraction was independently predicted by monocyte subpopulation 2. As lower counts depicted negative ventricular remodelling, this suggests a possible myofibroblast deposition and angiogenesis role for the newly described intermediate monocyte subpopulation Mon2 as opposed to the previously anticipated inflammatory role.

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Background: Monocytes are implicated in the initiation and progression of theatherosclerotic plaque contributing to plaque instability and rupture. Little is knownof the role played by the 3 phenotypically and functionally different monocytesubpopulations in determining ventricular remodeling following ST elevation my-ocardial infarction (STEMI). Mon1 are "classical" inflammatory monocytes, whilstMon3 are considered reparative with fibroblast deposition ability. The function ofthe newly described Mon2 is yet to be elucidated. Method: STEMI patients (n=196, mean age 62±13 years; 72% male) treatedwith percutaneous revascularization were recruited within the first 24 hours. Pe-ripheral blood monocyte subpopulations were enumerated and characterizedusing flow cytometry after staining for CD14, CD16 and CCR2. Phenotypi-cally, monocyte subpopulations are defined as: CD14+CD16-CCR2+ (Mon1),CD14+CD16+CCR+ (Mon2) and CD14lowCD16+CCR2- (Mon3) cells. Transtho-racic 2D echocardiography was performed within 7 days and 6 months post infarctto assess ventricular volumes, mass, systolic, and diastolic functions. Results: Using linear regression analysis higher counts for Mon1, and lowercounts for Mon2 and Mon3 were significantly associated with the baseline leftventricular ejection fraction (LVEF) within seven days post infarction. At 6 monthspost STEMI lower counts of Mon2 remained positively associated with decreasedLVEF (p value= 0.002).Monocyte subsets correlation with LVEFMonocytes mean florescence Baseline left ventricular Left ventricular ejectionintensity (cells/μl) ejection fraction (%) fraction (%) at 6 months post infarctβ-value P-valueβ-value P-valueTotal Mon0.31 P<0.001 0.360.009Mon 10.019 0.020.070.62Mon 2−0.28 0.001 −0.420.002Mon 3−0.27 0.001 −0.180.21 Conclusion: Peripheral monocytes of all three subsets correlate with LVEF af-ter a myocardial infarction. High counts of the inflammatory Mon1 are associatedwith reduction in the baseline LVEF. Post remodelling, the convalescent EF wasindependently predicted by monocyte subpopulation 2. As lower counts depictednegative ventricular remodeling, this suggests a reparative role for the newly de-scribed Mon2, possibly via myofibroblast deposition and angiogenesis, in contrastto an anticipated inflammatory role.

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A successful and useful treatment for end-stage heart failure is Left ventricular assist device (LVAD). An important part - a hydrodynamically suspended impeller exposed to corrosive conditions, required to sealed hermetically into micro packages. Laser beam welded (LBW) Ti6Al4V alloy has been adopted in anti-corrosion micro packages for the impeller of a (LVAD). Thin and narrow welds were required for such medical equipment. Pulsed Nd:YAG welding was successfully adopted as sealing method for the impeller. ©2011 IEEE.

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© The European Society of Cardiology 2015. Funding The project was funded by the Sir Halley Stewart Trust. MINAP is funded by the Health Quality Improvement Partnership (HQIP).

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Thesis (Master's)--University of Washington, 2016-08

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Inflammatory bowel disease (IBD) patients are at increased risk of developing thromboembolic complications. We report here a rare case of left ventricle thrombus in a young woman with ulcerative colitis. We discuss the pathophysiology of hypercoagulable state in IBD, and briefly address current prophylactic anticoagulation recommendations.

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Background: Reliable diagnostic measures for the evaluation of left ventricular systolic performance in the setting of altered myocardial loading characteristics in sickle cell anaemia remains unresolved. Objective: The study was designed to assess left ventricular systolic function in adult sickle cell patients using non-invasive endsystolic stress – end-systolic volume index ratio. Methods: A descriptive cross sectional comparative study was done using 52 patients recruited at the adult sickle cell anaemia clinic of the University of Nigeria Teaching Hospital Enugu. An equal number of age and sex-matched healthy volunteers served as controls. All the participants had haematocrit estimation, haemoglobin electrophoresis, as well as echocardiographic evaluation. Result: The mean age of the patients and controls were 23.93 ± 5.28 (range 18-42) and 24.17 ± 4.39 (range 19 -42) years respectively, (t = 0.262; p= .794). No significant difference was seen in estimate of fractional shortening, and ejection fraction. The cardiac out-put, cardiac index and velocity of circumferential shortening were all significantly increased in the cases compared with the controls. The end systolic stress – end systolic volume index ratio (ESS/ESVI) was significantly lower in cases than controls. There were strong positive correlation between the ejection phase indices (ejection fraction and fractional shortening) and end systolic stress and ESS/ESVI. Conclusion: The study findings suggest the presence of left ventricular systolic dysfunction in adult sickle cell anaemia. This is best detected using the loading-pressures independent force-length relationship expressed in ESS/ESVI ratio.

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Background. There is a growing need to improve heart preservation benefit the performance of cardiac operations, decrease morbidity, and more important, increase the donor pool. Therefore, the objective of this study was to evaluate the cardioprotective effects of Krebs-Henseleit buffer (KHB), Bretschneider-HTK (HTK), St. Thomas No. 1 (STH-1), and Celsior (CEL) solutions infused at 10 degrees C and 20 degrees C. Methods. Hearts isolated from male albino Wistar rats and prepared according to Langendorff were randomly divided equally into 8 groups according to the temperature of infusion (10 degrees C or 20 degrees C) and cardioprotective solutions (KHB, HTK, STH-1, and CEL). After stabilization with KHB at 37 degrees C, baseline values were collected (control) for heart rate (HR), left ventricle systolic pressure (LVSP), coronary flow (CF), maximum rate of rise of left ventricular pressure during ventricular contraction (+dP/dt) and maximum rate of fall of left ventricular pressure during left ventricular relaxation (-dP/dt). The hearts were then perfused with cardioprotective solutions for 5 minutes and kept for 2 hours in static ischemia at 20 degrees C. Data evaluation used analysis of variance (ANOVA) in all together randomized 2-way ANOVA and Tukey's test for multiple comparisons. The level of significance chosen was P < .05. Results. We observed that all 4 solutions were able to recover HR, independent of temperature. Interestingly, STH-1 solution at 20 degrees C showed HR above baseline throughout the experiment. An evaluation of the corresponding hemodynamic values (LVSP, +dP/dt, and -dP/dt) indicated that treatment with CEL solution was superior at both temperatures compared with the other solutions, and had better performance at 20 degrees C. When analyzing performance on CF maintenance, we observed that it was temperature dependent. However, when applying both HTK and CEL, at 10 degrees C and 20 degrees C respectively, indicated better protection against development of tissue edema. Multiple comparisons between treatments and hemodynamic variable outcomes showed that using CEL solution resulted in significant improvement compared with the other solutions at both temperatures. Conclusion. The solutions investigated were not able to fully suppress the deleterious effects of ischemia and reperfusion of the heart. However, these results allow us to conclude that temperature and the cardioprotective solution are interdependent as far as myocardial protection. Although CEL solution is the best for in myocardial protection, more studies are needed to understand the interaction between temperature and perfusion solution used. This will lead to development of better and more efficient cardioprotective methods.