626 research outputs found
Current clinical application of intracardiac flow analysis using echocardiography
No full textIn evaluating the cardiac function, it is important to have a comprehensive assessment of structural factors, such as the myocardial or valvular function and intracardiac flow dynamics that pass the heart. Vortex flow that form during left ventricular filling have specific geometry and anatomical location that are critical determinants of directed blood flow during ejection. The formation of abnormal vortices relates to the abnormal cardiac function. Therefore, vortex flow may offer a novel index of cardiac dysfunction. Intracardiac flow visualization using ultrasound technique has definite advantages with a higher temporal resolution and availability in real time clinical setting. Vector flow mapping based on color-Doppler and contrast echocardiography using particle image velocimetry is currently being used for visualizing the intracardiac flow. The purpose of this review is to provide readers with an update on the current method for analyzing intracardiac flow using echocardiography and its clinical applications
Differences in aortic vortex flow pattern between normal and patients with stroke: qualitative and quantitative assessment using transesophageal contrast echocardiography
No full textThe flow in the aorta forms a vortex, which is a critical determinant of the flow dynamics in the aorta. Arteriosclerosis can alter the blood flow pattern of the aorta and cause characteristic alterations of the vortex. However, this change in aortic vortex has not yet been studied. This study aimed to characterize aortic vortex flow pattern using transesophageal contrast echocardiography in normal and stroke patients. A total of 85 patients who diagnosed with ischemic stroke and 16 normal controls were recruited for this study. The 16 normal control subjects were designated as the control group, and the 85 ischemic stroke patients were designated as the stroke group. All subjects underwent contrast transesophageal echocardiography (TEE), and particle image velocimetry was used to assess aortic vortex flow. Qualitative and quantitative analyses of vortex flow morphology, location, phasic variation, and pulsatility were undertaken and compared between the groups. In the control group, multiple irregularly-shaped vortices were observed in a peripheral location in the descending thoracic aorta. In contrast, the stroke group had a single, round, merged, and more centrally located aortic vortex flow. In the quantitative analysis of vortex, vortex depth, which represents the location of the major vortex in the aorta, was significantly higher in the control group than in the stroke group (0.599\ua0±\ua00.159 vs. 0.522\ua0±\ua00.101, respectively, P\ua0=\ua00.013). Vortex relative strength, which is the pulsatility parameter of the vortex itself, was significantly higher in the stroke group than in the control group (0.367\ua0±\ua00.148 vs. 0.304\ua0±\ua00.087, respectively, P\ua0=\ua00.025). It was feasible to visualize and quantify the characteristic morphology and pulsatility of the aortic vortex flow using contrast TEE, and aortic vortex pattern significantly differed between normal and stroke patients
Usefulness of Left Ventricular Vortex Flow Analysis for Predicting Clinical Outcomes in Patients with Chronic Heart Failure: A Quantitative Vorticity Imaging Study Using Contrast Echocardiography
No full textThe goal of the study described here was to evaluate whether left ventricular vortex flow parameters, as assessed by contrast echocardiography, enhance prediction of major adverse cardiac events (MACE) in patients with chronic heart failure and systolic dysfunction. A total of 75 patients with contrast echocardiography and systolic dysfunction (ejection fraction 45%) were prospectively enrolled and underwent vortex flow analysis with particle image velocimetry using contrast echocardiography. Vortex flow parameters, including kinetic energy fluctuation (KEF), were evaluated. Patients were followed up for a primary endpoint of MACE that comprised hospital admission for cardiovascular causes and cardiac deaths. Across a median 277-d follow-up, 29 patients (38.7%) experienced MACE. Among these, the incidence of diabetes and the E/e’ ratio were significantly higher in patients with MACE than in those without, whereas the hemoglobin level and ejection fraction were significantly lower. KEF was significantly lower in patients with MACE. In the multivariate analysis, higher KEF was associated with a lower risk of MACE (hazard ratio = 0.18, 95% confidence interval: 0.040.97, p = 0.046). The addition of KEF to a model with conventional parameters (e.g., age, diabetes, ejection fraction and the E/e’ ratio) significantly improved the model’s discrimination. Elevations in the quantitative left ventricular vortex flow parameter, KEF, as determined by contrast echocardiography, are associated with a lower risk of MACE and improved functional status among patients with chronic heart failure
Neural tracts injuries in patients with hypoxic ischemic brain injury: Diffusion tensor imaging study
No full textMany studies have reported on vulnerable areas of the brain in hypoxic ischemic brain injury (HI-BI). However, little is known about the involvement of neural tracts following HI-BI. We investigated neural tract injuries in adult patients with HI-BI, using diffusion tensor tractography (DTT). Twelve consecutive patients with HI-BI and 12 control subjects were recruited for this study. We classified the patients into two subgroups according to the preservation of alertness: subgroup A-5 patients who had intact alertness and subgroup B-7 patients who had impaired alertness. DTI-Studio software was used for evaluation of seven neural tracts: corticospinal, cingulum, fornix, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and optic radiation. We measured the DTT parameters (fractional anisotropy, apparent diffusion coefficient and voxel number) of each neural tract. In the individual analysis, all 12 patients showed injuries in all 24 neural tracts in terms of both DTT parameters and integrity, except for the corticospinal tract (75.0% injury). In the group analysis, the patient group showed neural injuries in all 24 neural tracts. In comparison of subgroups A and B, subgroup B showed more severe injuries: subgroup B showed a higher rate of disruption (39.8%) than subgroup A (12.9%) on individual DTTs and subgroup B had more severe injuries in both the cingulum and superior longitudinal fasciculus. In conclusion, we found that extensive injuries in the neural tracts were accompanied by HI-BI. Patients with impaired alertness appeared to show more severe injuries of neural tracts. © 2012 Elsevier Ireland Ltd.
Intraventricular Flow: More than Pretty Pictures
No full textPatients with heart failure show myocardial, valvular, and electrical dysfunction, which results in enlarged cardiac chambers and increased intracardiac volume and pressure. Intracardiac flow analysis can provide information regarding the shape and wall properties, chamber dimensions, and flow efficiency throughout the cardiac cycle. There is increasing interest in vortex flow analysis for patients with heart failure to overcome limitations of conventional parameters. In conjunction with the conventional structural and functional parameters, vortex flow analysis-guided treatment in heart failure might be a novel option for cardiac physicians.restrictio
Transcatheter Mitral Valve Repair: Growing Evidence Regarding It's Efficacy and Optimal Indication
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1-D polymer containing the [Ru-N-Ru] μ-nitrido moiety: Crystal structure and magnetic properties of {[Cu(en)2]3[Ru2N(CN)10]·ClO4}n (en = 1,2-diaminoethane)
No full textA novel (μ-nitrido-diruthenium)-bridged 1-D coordination polymer was formed from reaction of K 5[Ru 2N(CN) 10] with [Cu(en) 2](ClO) 4) 2; a similar reaction with [Cu(pn) 2][(ClO) 4) 2] (pn = 1,3-diaminopropane) gave {[Cu(pn) 2] 5[Ru 2N(CN) 10] 2} as a discrete molecular compound; variable temperature susceptibility measurements show that there is a weak ferromagnetic interaction between the Cu(II) ions in 1-D polymer.link_to_subscribed_fulltex
Immediate and Evolutionary Recovery of Left Ventricular Diastolic Function after Transcatheter Aortic Valve Replacement: Comparison with Surgery
No full textPURPOSE:
We aimed to compare the effect of transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (sAVR) on recovery of left ventricular (LV) diastolic function and afterload through serial echocardiographic examinations in patients with symptomatic high-risk severe aortic stenosis during early follow-up.
MATERIALS AND METHODS:
We included 38 patients undergoing TAVR (mean age, 80±6 years; male:female=18:20) and 27 patients undergoing sAVR (mean age, 78±3 years; male:female=12:15). We compared changes in the LV diastolic function and afterload before, immediately after, and 3 months after the procedure using serial transthoracic echocardiography.
RESULTS:
Immediately after the procedure, 16 (42%) and 3 (11%) patients in the TAVR and sAVR groups, respectively, showed rapid improvement in diastolic filling patterns. E wave to e' ratio (E/e') and right ventricular systolic pressure (RVSP) decreased significantly in the TAVR group (E/e': TAVR, from 24.6±12.9 to 20±9.5, p=0.048 vs. sAVR, from 21.5±9.4 to 20.64±6.4, p=0.361; RVSP: TAVR, 38.4±17.2 vs. 34±12.4, p=0.032 vs. sAVR, 32.2±11.7 vs. 30±6.8, p=0.27). After 3 months, diastolic grade distribution, E/e', and RVSP were similar. Valvuloarterial impedance significantly decreased immediately after the procedure in both groups (TAVR, from 5.1±1.4 to 3.1±1.0 vs. sAVR, from 4.5±1.5 to 3.1±0.8 mm Hg · mL⁻¹ · m⁻², p=0.001), but after 3 months, decreases were greater in the sAVR group (from 3.1±0.8 to 2.2±1.5 mm Hg · mL⁻¹ · m⁻², p=0.093).
CONCLUSION:
LV diastolic function improved more rapidly and earlier in patients treatment with TAVR than in patients treated with sAVR. These results might explicate the remarkable clinical improvement in improvements in advanced diastolic dysfunction immediately after the TAVR procedure than sAVR.ope
Jia ru ju he wu dui jun yun tuan liu ji jun yun tuan liu dui liu de ying xiang
No full textWong, Chai Kwok = 加入聚合物對均勻湍流及均勻湍流對流的影響 / 黃濟國.Thesis M.Phil. Chinese University of Hong Kong 2013.Includes bibliographical references (leaves 89-91).Abstracts also in Chinese.Title from PDF title page (viewed on 01, November, 2016).Wong, Chai Kwok = Jia ru ju he wu dui jun yun tuan liu ji jun yun tuan liu dui liu de ying xiang / Huang Jiguo
Timing and Indications for Aortic Valve Surgery in Korean Bicuspid Aortic Valve Patients
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