239 research outputs found

    Percutaneous Coronary Intervention for Chronic Total Occlusion

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    Treatment of coronary chronic total occlusions represents one of the major challenges in the field of interventional cardiology. This is due to the complexity of these procedures and to the relatively higher risk of complications. In recent years, the development of innovative techniques and the evolution of materials have produced significant progress in this field. Better procedural outcomes have been achieved, with fewer complications. This article highlights the most recent scientific evidence and techniques, with the intention to guide interventional cardiologists in optimal patient selection and procedure choice

    Serial Morphological and Functional Assessment of Drug-Eluting Balloon for In-Stent Restenotic Lesions Mechanisms of Action Evaluated With Angiography, Optical Coherence Tomography, and Fractional Flow Reserve

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    ObjectivesThis study sought to elucidate the underlying mechanism through which drug-eluting balloons (DEB) restore coronary blood flow, by assessing the coronary vessel before, immediately after, and at 6-month follow-up with angiography, optical coherence tomography (OCT), and fractional flow reserve (FFR).BackgroundIn-stent restenosis (ISR) treatment remains challenging. Drug-eluting balloons have been shown to be a valid treatment option in several studies. These studies focused on efficiency of the device, whereas the mechanisms of action of DEB in ISR treatment have not been investigated.MethodsIn this prospective, single-center observational study, patients with ISR were treated with a second-generation DEB. Serial angiographic, OCT, and FFR measurements were performed before and after the procedure, as well as at 6-month follow-up.ResultsTwenty-five patients were assigned to DEB treatment, with an angiographic and device success of 100% and 92%, respectively. Late luminal loss was 0.01 ± 0.43 mm. Median percent changes [interquartile range] between pre-and post-procedure, and post-procedure and follow-up were, respectively: lumen volume 75.1% increase [43.7 to 115.0], and 8% increase [−14.0 to 25.8]; stent volume 23.7% increase [15.5 to 40.0], and −1.2% decrease [−6.9 to 5.9]; and neointimal volume −14.4% decrease [−29.2 to −9.5], and −15.8% decrease [−38.1 to 28.3]. The FFR gradient along the treated stent (difference in FFR between the distal and the proximal stent edge) was 0.37 ± 0.18 pre-procedure, 0.06 ± 0.04 post-procedure, and 0.05 ± 0.05 at follow-up. In all post-procedural OCT images, intrastent dissections were seen, which were sealed at follow-up OCT.ConclusionsDEB restore coronary blood flow by means of a short-term mechanical effect, causing an increase in lumen and stent volumes and compression of neointimal hyperplasia (with intra-stent dissections). Due to the local drug effect, patency persists and may even improve at follow-up, with further increase in lumen volume, decrease in neointimal volume, and complete sealing of neointimal dissections

    In-vivo, cardiac-cycle related intimal displacement of coronary plaques assessed by 3-D ECG-gated intravascular ultrasound: Exploring its correlate with tissue deformability identified by palpography

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    Background: ECG-gated image acquisition of intravascular ultrasound (IVUS) has been shown to provide more accurate measurements at different phases of the cardiac cycle. Objective: We sought to explore the ability dynamic assessment of ECG-gated 3-D IVUS to identify deformable regions of coronary plaques, by testing the hypothesis that at a given pressure and region, a faster displacement of the intima would correspond to high strain (soft tissue) regions assessed by palpography. Methods: ECG-gated 3-D IVUS and palpograms were acquired using 30 and 20 MHz IVUS imaging catheters respectively. Frames with high and/or low strain spots identified by palpography were randomly selected and the spots were assigned to a respective quadrant within the cross section. A color-blinded side-by-side view was performed to enable the co-localization of the same region. Subsequently, the pressure driven displacement of the intima was established for each quadrant and a binary score (significant displacement or no displacement) was decided. Results: One hundred and twenty-four quadrants were studied and the prevalence of highly deformable quadrants was low (n=7, 5.6% of the total). The sensitivity, specificity, positive predictive value and negative predictive value of 3-D ECG-gated IVUS to detect deformable quadrants as assessed by palpography were 42.9, 87.2, 16.7, and 96.2% respectively. Conclusion: In this pilot in vivo study, the intimal displacement velocity in the radial direction assessed by gray-scale 3-D ECG-gated IVUS failed to correlate with highly deformable regions. However, these preliminary findings suggest that the absence of significant displacement of the intima might be accurate to predict the absence of deformable tissue

    Расчет электромагнитного поля в электронных модулях с использованием интеграла Зоммерфельда

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    Излагается подход с использованием интеграла Зоммерфельда. Метод позволяет избежать интегрирования в комплексной области и снизить объем вычислений по сравнению с известными методами

    Уникальные ресурсы Крыма как основа для развития мистического туризма

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    Целью статьи является рассмотрение возможности развития мистического туризма в Крыму на основе его уникальных природных и культурно-исторических ресурсов
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