289 research outputs found
A probabilistic model to evaluate the resilience of unattended machinery plants in autonomous ships
Over the next few years, digitalization and automation are expected to be key drivers for maritime transport innovation to be key drivers for maritime transportation innovation. This revolutionary shift in the shipping industry will heavily impact the reliability of the machinery which is intended to be operated remotely with minimum support from humans. Despite a large amount of research into autonomous navigation and control systems in maritime transportation, the evaluation of unattended engine rooms has received very little attention. For autonomous vessels to be effective during their unmanned mission, it is essential for the engine room understand its health condition and self-manage performance. The unattended machinery plant (UMP) should be resilient enough to have the ability to survive and recover from unexpected perturbations, disruptions, and operational degradations. Otherwise, the system may require unplanned maintenance or the operation will stop. Therefore, the UMP must continue its operation without human intervention and safely return the ship to port. This paper aims to develop a machine learning-based model to predict an UMP's performance and estimate how long the engine room can operate without human assistance. A Random Process Tree is used to model failures in the unattended components, while a Hierarchical Bayesian Inference is adopted to facilitate the prediction of unknown parameters in the process. A probabilistic Bayesian Network developed and evaluated the dependent relationship between active and standby components to assess the effect of redundant units in the performance of unattended machinery. The present framework will provide helpful additional information to evaluate the associate uncertainties and predict the untoward events that put the engine room at risk. The results highlight the model's ability to predict the UMP's trusted operation period and evaluate an unattended engine room's resilience. A real case study of a merchant vessel used for short sea shipping in European waters is considered to demonstrate the model's application.</p
Prevalence and Incidence of Atrial Fibrillation in Heart Failure with Mildly Reduced or Preserved Ejection Fraction:(Additive) Value of Implantable Loop Recorders
BACKGROUND: Atrial fibrillation (AF) is common in heart failure with mildly reduced or preserved ejection fraction (HFmrEF/HFpEF) and has a negative impact on outcome. Reliable data on prevalence, incidence, and detection of AF from contemporary, prospective HFmrEF/HFpEF studies are scarce.METHODS: This was a prespecified sub-analysis from a prospective, multicenter study. Patients with HFmrEF/HFpEF underwent 12-lead electrocardiography (ECG), 24 h Holter monitoring, and received an implantable loop recorder (ILR) at the study start. During the 2 year follow-up, rhythm monitoring was performed via ILR, yearly ECG, and two yearly 24 h Holter monitors.RESULTS: A total of 113 patients were included (mean age 73 ± 8 years, 75% HFpEF). At baseline, 70 patients (62%) had a diagnosis of AF: 21 paroxysmal, 18 persistent, and 31 permanent AF. At study start, 45 patients were in AF. Of the 43 patients without a history of AF, 19 developed incident AF during a median follow-up of 23 [15-25] months (44%; incidence rate 27.1 (95% confidence interval 16.3-42.4) per 100 person-years). Thus, after the 2-year follow-up, 89 patients (79%) had a diagnosis of AF. In 11/19 incident AF cases (i.e., 58%), AF was solely detected on the ILR. Yearly 12-lead ECG detected six incident AF cases and four of these cases were also detected on two yearly 24 h Holter monitors. Two incident AF cases were detected on an unplanned ECG/Holter.CONCLUSIONS: Atrial fibrillation is extremely common in heart failure with HFmrEF/HFpEF and may inform on symptom evaluation and treatment options. AF screening with an ILR had a much higher diagnostic yield than conventional modalities.</p
Tyrosine Kinase Inhibitors and Proton Pump Inhibitors:An Evaluation of Treatment Options
Tyrosine kinase inhibitors (TKIs) have rapidly become an established factor in oncology, and have been shown to be effective in a wide variety of solid and hematologic malignancies. Use of the oral administration route of TKIs offers flexibility and is convenient for the patient; however, despite these advantages, the oral route of administration also causes a highly relevant new problem. Acid-inhibitory drugs, such as proton pump inhibitors (PPIs), increase the intragastric pH, which may subsequently decrease TKI solubility, bioavailability, and treatment efficacy. Clear and practical advice on how to manage PPI use during TKI therapy is currently not available in the literature. Since PPIs are extensively used during TKI therapy, prescribers are presented with a big dilemma as to whether or not to continue the combined treatment, resulting in patients possibly being deprived of optimal therapy. When all pharmacological characteristics and data of either TKIs and PPIs are considered, practical and safe advice on how to manage this drug combination can be given
Assessment of sex-related differences and outcome in patients who underwent cryoballoon pulmonary vein isolation for atrial fibrillation:an observational cohort study
OBJECTIVES: Pulmonary vein isolation (PVI) is widely accepted as an effective and safe treatment for symptomatic atrial fibrillation (AF). However, data on sex-related differences and associations with clinical outcome and safety of PVI with cryoballoon ablation are limited. We sought to compare sexrelated efficacy and safety of cryoballoon ablation and identify sex-related associations with clinical outcomes. METHODS AND RESULTS: We included 650 consecutive patients with AF undergoing PVI with cryoballoon ablation at our institution between 2013 and 2017. The efficacy outcome was the first documented recurrence (>30 s) of AF, atrial flutter or atrial tachycardia (AF/AT) or repeat ablation during follow-up, after a 90-day blanking period. The safety outcome was the incidence of periprocedural complications. Mean age of the population was 58±10, and 210 (32.3%) patients were women. Women were older, had a higher body mass index, had more renal dysfunction and less coronary artery disease as compared with men. The rate of AF/AT recurrence was similar between women and men at 12-month follow-up (27.6% vs 24.8%, p=0.445). The incidence of periprocedural complications was higher in women (12.9% vs 4.6%; p<0.001), specifically groin haematomas and phrenic nerve palsy. On multivariate analysis, left atrial volume index (adjusted OR 1.05, 95% CI 1.00 to 1.10; p=0.032) was associated with the incidence of procedural complications in women. For men, no relation with complications could be found. CONCLUSION: The efficacy of cryoballoon ablation was similar between women and men; however, women had a higher risk of procedural complications
Dynamic location problems with limited look-ahead
Background Among the most frequently encountered mutations in dilated cardiomyopathy (DCM) are those in the lamin A/C (LMNA) gene. Our goal was to analyze the LMNA gene in patients with DCM and/or conduction disease referred to the cardiogenetics outpatient clinic and to evaluate the prevalence of LMNA mutations and their clinical expression. Methods and Results The LMNA gene was screened in 61 index patients. Eleven mutations (including 6 novel) were identified, mainly in the subgroup of familial DCM with cardiac conduction disease (3/10 index patients) and in patients with DCM and Emery-Dreifuss, Limb-Girdle, or unclassified forms of muscular dystrophy (7/8 index patients). In addition, a mutation was identified in 1 of 4 families with only cardiac conduction disease. We did not identify any large deletions or duplications.Genotype-phenotype relationships revealed a high rate of sudden death and cardiac transplants in carriers of the p.N 195K mutation. Our study confirmed that the p.R225X mutation leads to cardiac conduction disease with late or no development of DCM, underscoring the importance of this mutation in putative familial "lone conduction disease." Nearly one third of LMNA mutation carriers had experienced a thromboembolic event. Conclusions This study highlights the role of LMNA mutations in DCM and related disorders. A severe phenotype in p.N 195K mutation carriers and preferential cardiac conduction disease in p.R225X carriers was encountered. Because of the clinical variability, including the development of associated symptoms in time, LMNA screening should be considered in patients with DCM or familial lone conduction diseas
Distribution of Cardioembolic Stroke:A Cohort Study
Background: A cardiac origin in ischemic stroke is more frequent than previously assumed, but it is not clear which patients benefit from cardiac work-up if obvious cardiac pathology is absent. We hypothesized that thromboembolic stroke with a cardiac source occurs more frequently in the posterior circulation compared with thromboembolic stroke of another etiology. Methods: We performed a multicenter observational study in 3,311 consecutive patients with ischemic stroke who were enrolled in an ongoing prospective stroke registry of 8 University hospitals between September 2009 and November 2014 in The Netherlands. In this initiative, the so-called Parelsnoer Institute-Cerebrovascular Accident Study Group, clinical data, imaging, and biomaterials of patients with stroke are prospectively and uniformly collected. We compared the proportions of posterior stroke location in patients with a cardiac stroke source with those with another stroke etiology and calculated risk ratios (RR) with corresponding 95% CI with Poisson regression analyses. To assess which patient or disease characteristics were most strongly associated with a cardiac etiology in patients with ischemic stroke, we performed a stepwise backward regression analysis. Results: For the primary aim, 1,428 patients were eligible for analyses. The proportion of patients with a posterior stroke location among patients with a cardiac origin of their stroke (28%) did not differ statistically significant to those with another origin (25%), age and sex adjusted RR 1.16; 95% CI 0.96-1.41. For the secondary aim, 1,955 patients were eligible for analyses. No recent history of smoking, no hyperlipidemia, coronary artery disease, a higher age, and a higher National Institutes of Health Stroke Scale (NIHSS) score were associated with a cardiac etiology of ischemic stroke. Conclusions: We could not confirm our hypothesis that thromboembolic stroke localized in the posterior circulation is associated with a cardioembolic source of ischemic stroke, and therefore posterior stroke localization on itself does not necessitate additional cardiac examination. The lack of determinants of atherosclerosis, for example, no recent history of smoking and no hyperlipidemia, coronary artery disease, a higher age, and a higher NIHSS score are stronger risk factors for a cardiac source of ischemic stroke
Effects of a simple cardiac rehabilitation program on improvement of self-reported physical activity in atrial fibrillation - Data from the RACE 3 study
Background and aim: Physical inactivity is associated with an increased prevalence of atrial fibrillation (AF). We aim to evaluate whether cardiac rehabilitation (CR) motivates patients to become and stay physical active, and whether CR affects sinus rhythm maintenance and quality of life (QoL) in patients with persistent AF and moderate heart failure. Methods: In the Routine versus Aggressive risk factor driven upstream rhythm Control for prevention of Early atrial fibrillation in heart failure study patients were randomized to conventional or targeted therapy. Targeted therapy contained next to optimal risk factor management a 3-month CR program, including self-reported physical activity and counseling. Successful physical activity was assessed in the targeted group, defined as activity of moderate intensity >= 150 min/week, or >= 75 min/week of vigorous intensity. AF was assessed at 1 year on 7-days Holter monitoring, QoL using general health, fatigue and AF symptom questionnaires. Results: All 119 patients within the targeted group participated in the CR program, 106 (89%) completed it. At baseline 80 (67%) patients were successfully physical active, 39 (33%) were not. NTproBNP was lower in active patients. During 1-year follow-up physical active patients stayed active: 72 (90%) at 12 weeks, 72 (90%) at 1 year. Inactive patients became active: at 12 weeks 25 (64%) patients and 30 (77%) at 1 year. No benefits were seen on sinus rhythm maintenance and QoL for successful physical active patients. Conclusion: In patients with persistent AF and moderate heart failure participation in CR contributes to improve and to maintain physical activity. (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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