Background
Steam pops are a rare complication associated with radiofrequency (RF) ablation and are hard to predict. The aim of this study was to assess the influence of coverage between the RF ...ablation electrode and cardiac tissue on steam pop incidence and lesion size.
Methods and results
An ex vivo model using porcine cardiac preparations and contact force sensing catheters was designed to perform RF ablations at different coverage levels between the RF electrode and cardiac tissue. During coverage level I, only the distal part of the ablation electrode was in contact with tissue. During coverage level II half of the ablation electrode, and during coverage level III the entire ablation electrode was embedded in tissue. RF applications (n = 60) at different coverage levels I–III were systematically performed using the same standardized ablation protocol. Ablations during coverage level III resulted in a significantly higher rate of steam pops (100%) when compared to ablations during coverage level II (10%) and coverage level I (0%), log rank p < .001. Coverage level I ablations resulted in significantly smaller lesion depths, diameters, and impedance drops when compared to higher coverage level ablations, p < .001. In the controlled ex vivo model, there was no difference in applied contact force or energy between different coverage levels.
Conclusions
The level of coverage between RF electrode, cardiac tissue, and the surrounding fluid significantly influenced the incidence of steam pops in an ex vivo setup. Larger coverage between RF electrode and tissue resulted in significantly larger lesion dimensions.
Across Canada, the large number of people working and studying from home require reliable and fast internet access. The COVID-19 pandemic demonstrates the urgency of diminishing the ‘digital divide’ ...in Canada.
Key Messages * Key issues related to Canada’s security and defence agenda, which involve critical and essential infrastructure development, must be considered in the development and implementation of ...a Canadian Northern Corridor (CNC). * Canada’s northern and Arctic security and defence agenda is related to several key policy domains that are relevant from a CNC perspective. These include infrastructure development, climate change, Indigenous sovereignty and natural resource development. * A CNC will gain international attention and be internationally recognized as a strategy for Canada to assert its sovereignty over its Arctic territory, including the internationally disputed Northwest Passage. * The CNC advocates for the inclusion and participation of Indigenous communities. Thus, Indigenous Peoples will also carry a significant role in the monitoring and surveillance of accessibility within and to the North, improved through enhanced infrastructure development. * Canada’s investments in Arctic defence infrastructure are modest compared to those of its Russian and American neighbours. A CNC, potentially adding strategically important infrastructure in the Canadian North, will directly tie into the discourse of Arctic security and power relations. * In addition to natural disasters, the Canadian North is at significant risk of human-made disasters that pose serious prospective challenges for northerners and for federal and territorial governments. The CNC will likely foster the development of surveillance and monitoring assets. * The CNC rights-of-way could trigger security concerns regarding the impact of foreign investment as a security threat, especially if natural resource development is coupled with the development of strategic transportation hubs, such as ports along the coast of the Arctic Ocean. * CNC transportation infrastructure would also become a part of Canada’s defence strategy as it forms a potential key asset in the defence and safeguarding of Canada’s northern and Arctic regions. * Future research should identify the role of dual-use infrastructure (infrastructure that satisfies both military and civilian purposes) in the CNC context and also examine to what extent security and defence stakeholders should be involved in the CNC’s planning and implementation.
Aims
The aim of this retrospective cohort study was to assess the influence of early recurrence (ER) after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) on long‐term outcomes ...and to identify clinical variables associated with ER.
Methods
We retrospectively collected clinical and procedural data from 1285 patients with paroxysmal AF who underwent PVI from 2011 to 2016. Kaplan‐Meier, receiver operating characteristic (ROC) curve, logistic and Cox regression analyses were performed to analyze the influence of ER on long‐term outcomes.
Results
ER was observed in 13% of patients. Kaplan‐Meier analyses showed significantly different outcomes in 1285 patients with and without ER (49% vs 74%, log rank P < .01) and in 286 patients in the subgroup that underwent reablation (44% vs 79%, log rank P < .01). The hazard ratio (HR) of ER was 1.7 within 48 hours (5% of patients), 2.7 within 1 month (5%), 3.0 within 2 months (2%), and 6.4 within 3 months (1%) for late recurrence (LR), P < .01. ROC analysis (area under the curve AUC = 0.79) resulted in 70.3% sensitivity and 74.2% specificity for a 14‐day blanking period, and 53.1% sensitivity and 85.5% specificity for a 30‐day blanking period. Female patients (odds ratio OR 1.69, P < .01) and those with diabetes (OR 1.95, P = .01) were at higher risk for ER.
Conclusions
ER is observed in a substantial number of patients with paroxysmal AF after PVI and has a continuous direct effect on LR according to the timing of ER. Randomized trials are required to assess the safety and effects of reablations in a shortened blanking period on long‐term outcomes.
The targets of global CO2 reduction outline the importance of decarbonizing the heating and cooling sector, which consume half of the final energy in the European Union (EU). Consequently, heating ...network operators must adapt to growing requirements for carbon neutrality. Energy system modeling allows the simulation of individual network compositions and regulations, while considering electricity market signals for a more efficient plant operation. The district heating model, programmed for this work, covers a measured heat demand with peak load boiler, biomass-fired combined heat and power (CHP) plant, and biomass heating plant supply. The CHP plant reacts to electricity prices of the European Power Exchange market and uses a long-term heat storage to decouple heat and electricity production. This paper presents the results of three annual simulation scenarios aimed at carbon neutrality for the analyzed heating network. Two scenarios achieve a climate-neutral system by replacing the peak load boiler generation. The exclusive storage capacity expansion in the first scenario does not lead to the intended decarbonization. The second scenario increases the output of the CHP plant, while the third simulation uses the biomass heating plant supply. This additional heat producer enables a significant reduction in storage capacity and a higher CHP plant participation in the considered electricity market.
•Portable high-density EEG is performed at participants’ home from a group of healthy good sleepers.•Individual fingerprints in deep sleep EEG topography relate to individual differences in risk ...preferences.•Lower slow-wave activity over the right prefrontal cortex is associated with higher individual risk propensity.•Slow-wave activity over the right prefrontal cortex might serve as a dispositional indicator of self-regulatory ability.
In everyday life, we have to make decisions under varying degrees of risk. Even though previous research has shown that the manipulation of sleep affects risky decision-making, it remains unknown whether individual, temporally stable neural sleep characteristics relate to individual differences in risk preferences. Here, we collected sleep data under normal conditions in fifty-four healthy adults using a portable high-density EEG at participants’ home. Whole-brain corrected for multiple testing, we found that lower slow-wave activity (SWA, an indicator of sleep depth) in a cluster of electrodes over the right prefrontal cortex (PFC) is associated with higher individual risk propensity. Importantly, the association between local sleep depth and risk preferences remained significant when controlling for total sleep time and for time spent in deep sleep, i.e., sleep stages N2 and N3. Moreover, the association between risk preferences and SWA over the right PFC was very similar in all sleep cycles. Because the right PFC plays a central role in cognitive control functions, we speculate that local sleep depth in this area, as reflected by SWA, might serve as a dispositional indicator of self-regulatory ability, which in turn reflects risk preferences.
Existential social psychology studies show that awareness of one's eventual death profoundly influences human cognition and behaviour by inducing defensive reactions against end-of-life related ...anxiety. Much less is known about the impact of reminders of mortality on brain activity. Therefore we explored whether reminders of mortality influence subjective ratings of intensity and threat of auditory and painful thermal stimuli and the associated electroencephalographic activity. Moreover, we explored whether personality and demographics modulate psychophysical and neural changes related to mortality salience (MS). Following MS induction, a specific increase in ratings of intensity and threat was found for both nociceptive and auditory stimuli. While MS did not have any specific effect on nociceptive and auditory evoked potentials, larger amplitude of theta oscillatory activity related to thermal nociceptive activity was found after thoughts of death were induced. MS thus exerted a top-down modulation on theta electroencephalographic oscillatory amplitude, specifically for brain activity triggered by painful thermal stimuli. This effect was higher in participants reporting higher threat perception, suggesting that inducing a death-related mind-set may have an influence on body-defence related somatosensory representations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Wingless (Wnt) signaling is an important pathway in gliomagenesis and in the growth of stem-like glioma cells. Using immunohistochemistry to assess the translocation of β-catenin protein, we ...identified intranuclear staining suggesting Wnt pathway activation in 8 of 43 surgical samples (19%) from adult patients with glioblastoma and in 9 of 30 surgical samples (30%) from pediatric patients with glioblastoma. Wnt activity, evidenced by nuclear β-catenin in our cohort and high expression of its target AXIN2 (axis inhibitor protein 2) in published glioma datasets, was associated with shorter patient survival, although this was not statistically significant. We determined the effects of the porcupine inhibitor LGK974 on 3 glioblastoma cell lines with elevated AXIN2 and found that it reduced Wnt pathway activity by 50% or more, as assessed by T-cell factor luciferase reporters. Wnt inhibition led to suppression of growth, proliferation in cultures, and modest induction of cell death. LGK974 reduced NANOG messenger RNA levels and the fraction of cells expressing the stem cell marker CD133 in neurosphere cultures, induced glial differentiation, and suppressed clonogenicity. These data indicate that LGK974 is a promising new agent that can inhibit the canonical Wnt pathway in vitro, slow tumor growth, and deplete stem-like clonogenic cells, thereby providing further support for targeting Wnt in patients with glioblastoma.
Introduction
For radiofrequency (RF) ablation, the EP Shuttle® (Stockert GmbH, Freiburg, Germany), Ampere® (St. Jude Medical, St. Paul, MN, USA), and SmartAblate® (Biosense Webster, Diamond Bar, CA, ...USA) generator models are most frequently used in clinical practice. The aim of this study was to assess the correlation between selected and delivered RF power for different generators.
Methods and results
In an experimental setup, ablation catheters were connected to the EP Shuttle®, Ampere®, and SmartAblate® generators. The power delivered by the generators was measured using a current converter and an oscilloscope. The selected power displayed on the generator was compared to the actually delivered power measured by the experimental setup (n = 800 measurements). The offsets between selected and delivered power increased significantly with impedance (EP Shuttle®). For example, at a selected power of 30 W, the delivered power was 40.3 W (EP Shuttle®), 30.1 W (Ampere®), and 28.1 W (SmartAblate®) at an impedance of 200 Ω.
In addition, ablation lesions (n = 80) were created in ex vivo porcine cardiac muscle preparations. The resulting ablation lesion size was calculated in caliper measurements. When the EP Shuttle® generator was operated at 200 Ω, the resulting lesion size was significantly larger than at 100 Ω. There were no significant offsets between power delivery and lesion size when using the Ampere® or SmartAblate® generators.
Conclusions
The Ampere® and SmartAblate® generator models deliver accurate power as selected by the user. The power delivered by the EP Shuttle® generator exceeds the selected power by up to 40% depending on impedance. The findings were confirmed in ex vivo porcine heart experiments and should be considered in clinical practice.
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