36 research outputs found

    Right ventricular basal inflow and outflow tract diameters overestimate right ventricular size in subjects with sigmoid-shaped interventricular septum: a study using three-dimensional echocardiography

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    Sigmoid-shaped ventricular septum (SS), a frequently encountered minor abnormality in echocardiographic examinations of the elderly, may have some influence on RV shape. We aimed to determine the influence of SS on the accuracy of the 6 RV linear diameter measurements in the light of three-dimensional echocardiographic (3DE) RV volume. The aorto-septal angle (ASA) was measured in the parasternal long-axis view using two-dimensional echocardiography (2DE) as an index of SS in 70 patients without major cardiac abnormalities who were subdivided into 35 with SS (ASA ≤ 120°) and 35 without SS (NSS). We measured RV end-diastolic volume (RVEDV) using 3DE; in addition, using 2DE, we measured basal RV diameter, mid-cavity diameter, longitudinal diameter and end-diastolic area in the apical four-chamber view; proximal RV outflow tract (RVOT) diameter in the parasternal long-axis view; and proximal and distal RVOT diameters in the parasternal short-axis view. RVEDV did not differ between the SS and NSS groups. The SS group had greater basal RV diameter and proximal and distal RVOT diameters than the NSS group. RV mid-cavity diameter, longitudinal diameter, and end-diastolic area did not differ between the groups. Among the 2DE parameters of RV size, RV end-diastolic area was most strongly correlated with RVEDV (r = 0.67), followed by RV mid-cavity diameter (r = 0.58). When SS is present, the echocardiographic basal RV diameter and RVOT diameters overestimate RV size, and the measurement of RV end-diastolic area and mid-cavity diameter more correctly reflect 3D RV volume

    Nanostructured gold thin film electrode derived from surfactant-free gold nanoparticles for enhanced electrocatalysis

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    Electrodes composed of nanostructured surfaces have been shown to be promising electrocatalysts, offering enhanced catalytic activity. Gold nanoparticles (AuNPs) are often used to produce such a nanostructured surface. However, these are commonly prepared using a reductant and surfactant, often hindering the electrocatalytic application of the surface. In the present study, we fabricated a nanostructured gold thin film electrode derived from a solution of AuNPs containing only Au, H, and O, which was prepared by solution plasma processing in the presence of hydrogen peroxide. The concentrated AuNP dispersed aqueous solution was dropped onto the glassy carbon substrate and then dried to form a AuNP thin film at room temperature. The resultant gold film was nanostructured owing to the presence of the AuNPs, could be used directly in electrochemical reactions without pre-treatment (such as surfactant/reductant removal), and gave stable voltammetric responses, indicating its suitability as an electrode material. In addition, the AuNP thin film electrode exhibited enhanced electrocatalytic activity compared with conventional planar gold electrodes, which can be attributed to its surface nanostructure. In particular, the electrocatalytic current in the hydrogen evolution reaction was more than 10 times larger at the nanostructured AuNP thin film electrode than at a planar gold electrode. Further, the AuNP thin film electrode enabled direct electron transfer (DET) between a redox enzyme, neuroglobin, and the electrode surface, while the planar electrode showed no DET response. The results indicate the usefulness of the present AuNP thin film electrode, prepared by a reagent-free process, for various electrocatalytic applications

    Left ventricular global longitudinal strain calculated from manually traced endocardial border lengths utilizing the images for routine ejection fraction measurement by biplane method of disks

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    Purpose The purpose of this study was to test whether the fractional change in the endocardial border length between end-diastole and end-systole as manually traced in left ventricular ejection fraction (LVEF) measurement using the biplane method of disks (MOD) was consistent with the global longitudinal strain derived from speckle-tracking echocardiography. Methods For 105 patients who underwent echocardiography, two- and four-chamber images with manually traced endocardial lines for LVEF measurement by MOD were stored. LV endocardial lengths at end-diastole and at end-systole were measured on both images to calculate the fractional length changes, which were averaged (GLS(MOD)). Speckle-tracking analysis was performed to measure global longitudinal strains in the apical two- and four-chamber and long-axis images, and the three values were averaged (GLS(STE)) according to the ASE and EACVI guidelines. Results There was no significant difference between GLS(MOD) and GLS(STE). GLS(MOD) correlated well with GLS(STE) (r = 0.81, p < 0.001), and there was no fixed bias in the Bland-Altman analysis. The intraclass correlations for the intra- and inter-observer comparisons for GLS(STE) were excellent, and those for GLS(MOD) were adequate. Conclusion The fractional LV endocardial border length change, GLS(MOD), showed sufficient agreement with GLS(STE) to justify its use as a substitute for the STE-derived global longitudinal strain

    Spontaneous Echo Contrast and Thrombus Formation at the Carotid Bifurcation After Carotid Endarterectomy

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    Spontaneous echo contrast (SEC) consists of numerous microechoes swirling in the cardiovascular lumen and is usually seen during blood stasis in dysfunctional left atrium. However, SEC and consecutive local thrombus formation at the carotid artery early after carotid endarterectomy (CEA) have not been reported. This study retrospectively investigated the clinical importance and therapeutic strategy of postoperative SEC and thrombus formation in 113 consecutive patients who underwent CEA between 2001 and 2009. Ultrasonography was routinely performed preoperatively, intraoperatively, and 1 day and 1 week after the operation. If SEC and/or thrombus was detected at any time after the operation, follow-up ultrasonography was performed at short intervals, once a week for inpatients and once every 1-2 months for outpatients. Eight of the 113 patients (7%) had SEC after the operation from Day 1 to 12 (mean 7.2 days), and 6 of these 8 patients developed local de novo thrombus formation at the site of SEC from Day 6 to 33 (mean 14.7 days). The maximum luminal narrowing by the thrombi were 26-62% (mean 37%). After administering anticoagulant therapy, all thrombi disappeared from Day 13 to 190 (mean 57 days) from CEA. SEC seen after CEA is highly associated with consecutive local thrombus formation. Postoperative geometric blood stasis with the absence of intima may be the causative factor for its development

    Altered oscillation of Doppler-derived renal and renal interlobar venous flow velocities in hypertensive and diabetic patients

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    Background and purpose Flow velocity oscillation rate (FVOR) of the renal interlobar vein has been reported to be decreased in patients with urinary obstruction or diabetic nephropathy, and increased in those with hypertension during pregnancy. To clarify the clinical role of the renal interlobar venous FVOR, we investigated the flow velocity patterns of the renal vessels in patients with hypertension (HT) and/or diabetes (DM). Methods and results Pulsed-wave Doppler sonography was performed in 34 patients: 15 with HT, 10 with DM, and nine with both HT and DM (HT-DM). Each FVOR of the right and left interlobar veins was closely and positively correlated with the ipsilateral interlobar arterial resistive index (RI), especially in the HT group, but not with the estimated glomerular filtration rate. The right interlobar venous FVOR was decreased in the DM and HT-DM groups compared to the HT group. Conclusion The renal interlobar venous FVOR is strongly influenced by the arterial RI in HT patients, and is reduced in DM patients without an obvious relationship with diabetic nephropathy. These findings should be noted for the clinical application of renal interlobar venous flow analysis

    Early diastolic mitral annular velocity at the interventricular septal annulus correctly reflects left ventricular longitudinal myocardial relaxation

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    Aims: Early diastolic mitral annular velocity (e') obtained by tissue Doppler imaging (TDI) is widely used to evaluate left ventricular (LV) diastolic function based on the assumption that it reflects myocardial relaxation in the long-axis direction. In this study, we aimed to determine whether or not e' truly reflects early diastolic longitudinal myocardial relaxation, and which is the most useful for evaluating LV diastolic function among e' measured at the interventricular-septal annulus (IS-e'), that measured at the lateral annulus (LW-e') or their mean value (M-e'). Methods and results: IS-e', LW-e', and M-e' were measured using colour TDI in 15 patients with hypertrophic cardiomyopathy, 13 patients with hypertension and 19 control subjects. Using two-dimensional speckle tracking imaging, early diastolic myocardial strain rates (SR_[E]) were measured for the IS (IS-SR_[E]), LW(LW-SR_[E]) and entire LV myocardium (G-SR_[E]). IS-e' was excellently correlated with IS-SR_[E] (r = 0.90, P < 0.001); the correlation was better than that between LW-e' and LW-SR_[E] (r = 0.75, P < 0.001). IS-e' and M-e' were well correlated with G-SR_[E] (r = 0.88, P < 0.001 and r = 0.86, P < 0.001, respectively) and with LV early diastolic flow propagation velocity (r = 0.77, P < 0.001 and r = 0.78, P < 0.001, respectively). The correlations of LW-e' to G-SR_[E] (r = 0.80, P < 0.001) and flow propagation velocity (r = 0.75, P < 0.001) did not reach this level. Conclusion: IS-e' well reflected LV longitudinal myocardial relaxation and LV diastolic function, and was found to be more useful in evaluating LV diastolic function than LW-e'

    Solitary Spinal Epidural Metastasis from Gastric Cancer

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    Solitary epidural space metastasis of a malignant tumor is rare. We encountered a 79-year-old male patient with solitary metastatic epidural tumor who developed paraplegia and dysuria. The patient had undergone total gastrectomy for gastric cancer followed by chemotherapy 8 months priorly. The whole body was examined for suspected metastatic spinal tumor, but no metastases of the spine or important organs were observed, and a solitary mass was present in the thoracic spinal epidural space. The mass was excised for diagnosis and treatment and was histopathologically diagnosed as metastasis from gastric cancer. No solitary metastatic epidural tumor from gastric cancer has been reported in English. Among the Japanese, 3 cases have been reported, in which the outcome was poor in all cases and no definite diagnosis could be made before surgery in any case. Our patient developed concomitant pneumonia after surgery and died shortly after the surgery. When a patient has a past medical history of malignant tumor, the possibility of a solitary metastatic tumor in the epidural space should be considered
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