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Background Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are attractive for preventing sudden cardiac death in hypertrophic cardiomyopathy (HCM) as they mitigate risks of transvenous leads in young patients. However, S-ICDs may be associated with increased inappropriate shock (IAS) in HCM patients. Objective The purpose of this study was to assess the incidence and predictors of appropriate shock and IAS in a contemporary HCM S-ICD cohort. Methods We collected electrocardiographic and clinical data from HCM patients who underwent S-ICD implantation at 4 centers. Etiologies of all S-ICD shocks were adjudicated. We used Firth penalized logistic regression to derive adjusted odds ratios (aORs) for predictors of IAS. Results Eighty-eight HCM patients received S-ICDs (81 for primary and 7 for secondary prevention) with a mean follow-up of 2.7 years. Five patients (5.7%) had 9 IAS episodes (3.8 IAS per 100 patient-years) most often because of sinus tachycardia and/or T-wave oversensing. Independent predictors of IAS were higher 12-lead electrocardiographic R-wave amplitude (aOR 2.55 per 1 mV; 95% confidence interval 1.15–6.38) and abnormal T-wave inversions (aOR 0.16; 95% confidence interval 0.02–0.97). There were 2 appropriate shocks in 7 secondary prevention patients and none in 81 primary prevention patients, despite 96% meeting Enhanced American College of Cardiology/American Heart Association criteria and the mean European HCM Risk-SCD score predicting 5.7% 5-year risk. No patients had sudden death or untreated sustained ventricular arrhythmias. Conclusion In this multicenter HCM S-ICD study, IAS were rare and appropriate shocks confined to secondary prevention patients. The R-wave amplitude increased IAS risk, whereas T-wave inversions were protective. HCM primary prevention implantable cardioverter-defibrillator guidelines overestimated the risk of appropriate shocks in our cohort.

Background and purpose We sought to investigate whether there are gender differences in clinical outcome after stroke due to large vessel occlusion (LVO) after mechanical thrombectomy (EVT) in a large population of real-world patients. Methods From the Italian Registry of Endovascular Thrombectomy, we extracted clinical and outcome data of patients treated for stroke due to large vessel occlusion. We compared clinical and safety outcomes in men and women who underwent EVT alone or in combination with intravenous thrombolysis (IVT) in the total population and in a Propensity Score matched set. Results Among 3422 patients included in the study, 1801 (52.6%) were women. Despite older age at onset (mean 72.4 vs 68.7; p Conclusions Subject to the limitations of a non-randomized comparison, women with stroke due to LVO treated with mechanical thrombectomy had a better chance to achieve complete recanalization, and 3-month functional independence than men. The results could be driven by women who underwent combined treatment.

Funding Acknowledgements Type of funding sources: None. Background A high incidence of pulmonary vein (PV) reconnection has been reported in patients with clinical recurrences of AF. Detailed characterization of PV gaps in terms of local impedance (LI) is still lacking. Purpose to characterize PV gaps with a novel local impedance algorithm during redo PV ablation in AF patients (pts). Methods Consecutive pts undergoing repeated AF ablation from the CHARISMA registry with complete characterization of PV gaps through local impedance at 6 Italian centers were included. A complete map of the left atrium and PVs was performed prior and after ablation through the Rhythmia mapping system. A novel RF ablation catheter with dedicated algorithm (DirectSense) was used to measure LI at the distal electrode of this catheter. Each gap was characterized in terms of LI and its variations during ablation procedure according to different ablation sites around the PVs. 7 sites around the left and right pair of PV for LI evaluation during ablation were defined: 2 for posterior sites (PS) (posterior inferior and posterior superior), 2 for anterior sites (AN) (anterior inferior and anterior superior), 1 for interior site (INF), 1 for superior site (SUP) and 1 for the carina (CAR). Ablation endpoint was PVI as assessed by entrance and exit block. Results Eighteen cases of redo AF ablation were analyzed (9 after prior RF ablation, 9 after prior cryoablation). A total of 41 PV gaps were detected (20 after RF ablation, 21 after cryoablation; mean number of gaps per pt = 2.3 ± 1.1): one gap was identified In five (27.8%) pts, 2 gaps were present in 7 (38.9%) pts, 3 gaps were detected in 2 (11.1%) pts and 4 gaps were identified in the remaining 4 (22.2%) pts. PV gaps were most common at AN sites (17, 41.5%), followed by PS sites (12, 29.3%) and CAR sites (11, 28.6%). The mean LI at gap sites was 113.9 ± 15Ω prior to ablation: it was significantly higher than LI at scar tissue closer to gap (99.7 ± 8Ω, p Conclusion In our preliminary experience, PV gaps after failed PVI were most common at anterior, followed by posterior and carina sites. LI characteristics at PV gaps significantly differ from both scar and healthy tissue and could be used to target ablation deliveries.

Concrete behaves as a brittle material due to its low inherent tensile strength, but it can also exhibit a markedly ductile behavior when coupled with transverse reinforcement like steel stirrups. The role of stirrups is to enhance confinement effect, to restrain the lateral expansion of concrete, thus modifying the concrete stress-strain constitutive law and enabling higher compression strains and higher ductility. This paper focuses on the confinement effect induced by different arrangements of transverse reinforcement on axially loaded concrete columns. An experimental campaign has been carried out, comprising 18 concrete columns with two different mechanical strengths and reinforced with three different layouts of stirrups, namely typical closed square hoops, closed stirrups with additional cross ties, and a novel type of stirrups involving rectangular hoops with additional restraint plates, the latter offering an enhanced diffused confinement action and limiting extensive spalling of the cover concrete. Formation and propagation of longitudinal micro-cracks are reduced with the novel type of diffused stirrups and a moderate-to-high increase of ductility is observed. However, the beneficial effects induced by diffused stirrups are more pronounced in medium-strength concrete and almost negligible in low-strength concrete that collapses due to a brittle cracking failure without involving the confinement action of the transverse reinforcement.

Aims Per standard of care, dual-chamber pacemakers are programmed in DDDR mode with fixed atrioventricular (AV) delay or with long AV delay to minimize ventricular pacing. We aimed to evaluate whether the PR interval may be a specific criterion of choice between standard DDDR, to preserve AV synchrony in long PR patients, and managed ventricular pacing (MVP), to avoid ventricular desynchronization imposed by right ventricle apical pacing, in short PR patients. Methods and results In the MINERVA trial, 1166 patients were randomized to Control DDDR, MVP, or atrial anti-tachycardia pacing plus MVP (DDDRP + MVP). We evaluated the interaction of PR interval with pacing mode by comparing the risk of atrial fibrillation (AF) longer than 7 consecutive days as a function of PR interval. Out of 906 patients with available data, the median PR interval was 180 ms. The PR interval was found to significantly (P = 0.012) interact with pacing mode for AF incidence: the risk of AF > 7 days was lower [hazard ratio (HR) 0.58, 95% confidence interval (95% CI) 0.34-0.99; P = 0.047] in patients with short PR (shorter than median PR) if programmed in MVP mode compared with DDDR mode and it was lower (HR 0.65, 95% CI 0.43-0.99; P = 0.049) in patients with long PR (equal to or longer than median PR) if programmed in DDDR mode compared with MVP. Conclusion Our data show that PR interval may be used as a selection criterion to identify the optimal physiological pacing mode. Persistent AF incidence was lower in short PR patients treated by right ventricular pacing minimization and in long PR patients treated by standard dual-chamber pacing.

The fracture behavior of lightweight foamed concrete (LWFC) is significantly influenced by microstructural properties, which are ascribed to the arrangement of air bubbles and pores as well as to the presence of different hydration products. In this contribution, an experimental investigation on the fracture behavior of LWFC is performed. Notched beams made of LWFC were tested in three-point bending to determine the fracture energy based on the load-CMOD (Crack Mouth Opening Displacement) curve. The influence of the dry density is explored considering one density for non-structural purposes (equal to 800 kg/m3) and another density for structural applications (1600 kg/m3). Moreover, two curing conditions are considered (air and water). The load-CMOD curves reveal that for lower dry densities the fracture behavior of LWFC is particularly affected by the curing conditions, with better results achieved in air curing conditions, but this influence decreases with higher dry densities. The improved performance in air curing conditions for lower dry densities is also observed in terms of flexural strength, but is not particularly evident for the compressive strength. Micrographs across the crack surface determined via Scanning Electron Microscopy (SEM) are finally presented to analyze the experimental findings and justify the results in terms of microstructural configuration of the specimens.

The earthquake protection of structures equipped with energy dissipation devices in the form of nonlinear fluid viscous dampers (FVDs) is investigated. Most of the optimal design strategies from the literature either address a simplified linear (Newtonian) idealization of the devices, or identify the characteristics of the nonlinear FVDs in a later stage, by invoking the concept of “energy-equivalent” dampers to compromise between the nonlinear power law force-velocity behavior and a simplified (equivalent, in terms of energy dissipation) linear modeling. In this paper, the nonlinear power law behavior of the devices is incorporated a priori in the optimal design process. The proposed strategy, based upon a numerical approach to a constrained optimization problem, invokes a performance criterion that is derived from the energy balance equation of the system, expressed in stochastic terms. To handle the nonlinear constitutive behavior of the FVDs, a novel equal-energy non-Gaussian stochastic linearization technique is integrated in the optimal design process. For a given power-spectral-density function of the seismic excitation, the most effective set of nonlinear FVDs that maximize the energy dissipation behavior can be identified. By stochastic dynamic analysis and by nonlinear response-history-analysis with an ensemble of ground motions, the proposed energy-based design philosophy is found to be better able to control the overall seismic response of the structure than alternative procedures that are not based on energy concepts and that minimize other performance indices.

It is hotly debated whose perspective is relevant for defining the truth-value of bare epistemic possibility statements: the utterer or the assessor. Central to this debate are findings on truth-value judgments of ‘might p’ statements in “eavesdropping” scenarios where the statement is appropriately asserted from the point of view of the speaker but does not correspond to how in reality things are. We offer findings from two studies suggesting that in these scenarios English speakers disagree on the truth-value not only of ‘might p’ but also, surprisingly, of bare ‘p’. We argue that underlying this behavior is not a disagreement on the semantic content of the statements but a disagreement on how to interpret the meaning of the adjectives ‘true’ and ‘false’ when applied to a statement uttered by another agent. Specifically, we compare two potential accounts: the first account ascribes to the adjective ‘true’ an ambiguity between a ‘coherent’ sense – a statement uttered by A is true as long as the statement coheres with A’s evidence – and a ‘correspondentist’ sense - a statement as uttered by A is true as long as the statement correspond to reality; the second account treats ‘true’ as having only the correspondentist sense but ascribes to it an inherent relative nature – to decide if a statement as uttered by A is true one has to first decide a perspective (A or the assessor). Lastly, we discuss the implications of the findings for the semantics of epistemic ‘might p’ statements.

The technique of direct intratumoral injection of permanent liquid agents has evolved significantly over the past few decades. The percutaneous direct puncture technique is being utilised more and more for embolisation of head and neck hypervascular lesions. We describe a case treated via the direct percutaneous transnasal (TN) puncture technique for embolisation of a sinonasal hypervascular tumour, performed in a 21-year-old male patient. Due to extensive vascularisation of the tumour, preoperative embolisation was requested by our otolaryngologist team in order to minimise intraoperative bleeding and reduce surgical morbidity. A primary attempt at trans-arterial embolisation through selective ophthalmic artery catheterisation was unsuccessful due to unfavourable anatomy. An extensive devascularisation of the nasal fossa lesion was obtained using a single injection of low-density polymeric embolic agent (SQUID®). Post-operative eradication was uneventful. Final histopathology exam revealed vascular tumour consistent with a rare sinonasal glomangiopericytoma. To our knowledge, this is the first reported case of a rare sinonasal glomangiopericytoma treated by direct TN injection, utilising the liquid polymer agent SQUID®.

Background: More and more heart failure (HF) patients aged ≥ 75 years undergo cardiac resynchronization therapy (CRT) device implantation, however the data regarding the outcomes and their predictors are scant. We investigated the mid- to long-term outcomes and their predictors in CRT patients aged ≥ 75 years. Methods: Patients in the Cardiac Resynchronization Therapy Modular (CRT MORE) Registry were divided into three age-groups: &lt, 65 (group A), 65–74 (group B) and ≥75 years (group C). Mortality, hospitalization, and composite event rate were evaluated at 1 year and during long-term follow-up. Results: Patients (n = 934) were distributed as follows: group A 242, group B 347, group C 345. On 12-month follow-up examination, 63% of patients ≥ 75 years displayed a positive clinical response. Mortality was significantly higher in patients ≥ 75 years than in the other two groups, although the rate of hospitalizations for HF worsening was similar to that of patients aged 65–74 (7 vs. 9.5%, respectively, p = 0.15). Independent predictors of death and of negative clinical response were age &gt, 80 years, chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD). Over long-term follow-up (1020 days (IQR 680-1362)) mortality was higher in patients ≥ 75 years than in the other two groups. Hospitalization and composite event rates were similar in patients ≥ 75 years and those aged 65–74 (9 vs. 11.8%, p = 0.26, and 26.7 vs. 20.5%, p = 0.06). Conclusion: Positive clinical response and hospitalization rates do not differ between CRT recipients ≥ 75 years and those aged 65–74. However, age &gt, 80 years, COPD and CKD are predictors of worse outcomes.

BACKGROUND AND PURPOSE: Intra-arterial DSA has been traditionally used for confirmation of cure following gamma knife radiosurgery for AVMs. Our aim was to evaluate whether 4D arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination can be an alternative to DSA for confirmation of AVM obliteration following gamma knife radiosurgery. MATERIALS AND METHODS: In this prospective study, 30 patients undergoing DSA for confirmation of obliteration following gamma knife radiosurgery for AVMs (criterion standard) also underwent MRA, including arterial spin-labeling MRA and contrast-enhanced time-resolved MRA. One dataset was technically unsatisfactory, and the case was excluded. The DSA and MRA datasets of 29 patients were independently and blindly evaluated by 2 observers regarding the presence/absence of residual AVMs. RESULTS: The mean time between gamma knife radiosurgery and follow-up DSA/MRA was 53 months (95% CI, 42–64 months; range, 22–168 months). MRA total scanning time was 9 minutes and 17 seconds. Residual AVMs were detected on DSA in 9 subjects (obliteration rate = 69%). All residual AVMs were detected on at least 1 MRA sequence. Arterial spin-labeling MRA and contrast-enhanced time-resolved MRA showed excellent specificity and positive predictive values individually (100%). However, their sensitivity and negative predictive values were suboptimal due to 1 false-negative with arterial spin-labeling MRA and 2 with contrast-enhanced time-resolved MRA (sensitivity = 88% and 77%, negative predictive values = 95% and 90%, respectively). Both sensitivity and negative predictive values increased to 100% if a composite assessment of both MRA sequences was performed. Diagnostic accuracy (receiver operating characteristic) and agreement (κ) are maximized using arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination (area under receiver operating characteristic curve = 1, P

Digital Image Correlation (DIC) provides measurements without disturbing the specimen, which is a major advantage over contact methods. Additionally, DIC techniques provide full-field maps of response quantities like strains and displacements, unlike traditional methods that are limited to a local investigation. In this work, an experimental application of DIC is presented to investigate a problem of relevant interest in the civil engineering field, namely the interface behavior between externally bonded fabric reinforced cementitious mortar (FRCM) sheets and concrete substrate. This represents a widespread strengthening technique of existing reinforced concrete structures, but its effectiveness is strongly related to the bond behavior between composite fabric and underlying concrete. To investigate this phenomenon, a set of notched concrete beams are realized, reinforced with FRCM sheets on the bottom face, subsequently cured in different environmental conditions (humidity and temperature) and finally tested up to failure under three-point bending. Mechanical tests are carried out vis-à-vis DIC measurements using two distinct cameras simultaneously, one focused on the concrete front face and another focused on the FRCM-concrete interface. This experimental setup makes it possible to interpret the mechanical behavior and failure mode of the specimens not only from a traditional macroscopic viewpoint but also under a local perspective concerning the evolution of the strain distribution at the FRCM-concrete interface obtained by DIC in the pre- and postcracking phase.

International audience; The anarchic hand syndrome refers to an inability to control the movements of one’s own hand, which acts as if it has a will of its own. The symptoms may differ depending on whether the brain lesion is anterior, posterior, callosal or subcortical, but the relative classifications are not conclusive. This study investigates the role of white matter disconnections in a patient whose symptoms are inconsistent with the mapping of the lesion site. A repeated neuropsychological investigation was associated with a review of the literature on the topic to identify the frequency of various different symptoms relating to this syndrome. Furthermore, an analysis of the neuroimaging regarding structural connectivity allowed us to investigate the grey matter lesions and white matter disconnections. The results indicated that some of the patient’s symptoms were associated with structures that, although not directly damaged, were dysfunctional due to a disconnection in their networks. This suggests that the anarchic hand may be considered as a disconnection syndrome involving the integration of multiple antero-posterior, insular and interhemispheric networks. In order to comprehend this rare syndrome better, the clinical and neuroimaging data need to be integrated with the clinical reports available in the literature on this topic. View Full-Text

Background Obesity, advanced age and left atrium dimensions have been linked to atrial fibrillation (AF). Purpose This study aimed at evidencing if the above mentioned risk factors have a role among the others in conditioning the onset of post operative AF (PoAF) in patients undergoing cardiac surgery without previous AF. Methods This study evaluated 249 consecutive patients undergoing coronary artery by-pass surgery either isolated or in combination with aortic or mitral valve repair/replacement, or isolated valve repair/replacement. Prior to surgery, in all patients the following data were collected: age (yrs), body mass index (BMI, kg/m2), left atrium (LA) diameter (cm), LA area (cm2), left ventricular ejection fraction (LVEF, %), the presence/absence of arterial hypertension (AH) and diabetes, creatinine (mg/dL). To detect the presence of PoAF, cardiac rhythm was continouosly recorded during the first seven postoperative days. Results PoAF occurred in 127 patients (51%). We compared patients with and without PoAF. Mean values (±1 SD) of continuous variables and the frequency of dicothomic ones are reported in the table. No difference was observed for sex, LA diameter, LA area, LVEF and diabetes. Instead, patients with PoAF had higher values of age, BMI, creatinine and a greater prevalence of AH. According to multivariable binary logistic analysis the independent predictors of PoAF were: age (OR = 1.05, CI 95%: 1.026–1.074, p=0.018) and BMI (OR = 1.09, CI 95%: 1.015–1.171, p=0.0001). Conclusions Results suggest that advanced age and a higher value of BMI could be strong risk factors for PoAF in patients who undergo cardiac surgery without previous AF. This considering that in the present population the values of LA diameter, LA area and LVEF showed no statistically significant difference between patients with and without PoAF. Funding Acknowledgement Type of funding source: None

Purpose. Myocardial scar is directly related to the response to CRT after implantation. The extent of myocardial scar can be detected not only by cardiac magnetic resonance but also by two electrocardiographic scores: fragmented QRS (fQRS) and Selvester score (SSc). The aim of our study is to compare the role of baseline SSc and fQRS in predicting response to CRT in a cohort of heart failure patients with true left bundle branch block (LBBB). As a secondary endpoint, we assessed the association of both scores with overall and cardiac mortality, heart failure hospitalizations, ventricular arrhythmias requiring ICD intervention, and major adverse cardiovascular event (MACE). Methods. We evaluated fQRS and SSc of 178 consecutive HF patients with severe systolic dysfunction (LVEF ≤ 35%), NYHA class II-III despite optimal medical treatment, and true-LBBB. Response to CRT was defined as the improvement of LVEF of at least 10% or as the reduction of LVESV of at least 15% at a 6-month follow-up. Each endpoint was related to fQRS and SSc. Results. SSc ≥7 was significantly associated with the absence of echocardiographic response to CRT (OR: 0.327; 95% C.I. 0.155–0.689; p = 0.003 ), while the presence of fQRS at baseline ECG was not (OR: 1.133; 95% C.I. 0.539–2.381; p = 0.742 ). No correlation was found between SSc and overall mortality, cardiac death, ventricular arrhythmias, hospitalizations due to heart failure, or for MACE. Similar results were observed between fQRS and all secondary endpoints. Conclusion. In HF patients with true-LBBB and LVEF ≤35% eligible for CRT, myocardial scar assessed by calculating the SSc on preimplant ECG is an independent predictor of nonresponse after multiple adjustments. Neither SSc nor fQRS is associated with overall and cardiac death, ventricular arrhythmias, or hospitalization for heart failure at a 24-month follow-up.

Funding Acknowledgements NO FUNDING OnBehalf RHYTHM DETECT Registry Background The class of recommendation for S-ICD implantation in patients who have inadequate vascular access is I according to AHA-ACC-HRS Guidelines and IIb according to ESC Guidelines. Data are lacking about the use of S-ICD for patients in which a transvenous ICD is not a viable option because of the inability to deploy a transvenous lead. Purpose To describe current practice and to measure outcomes associated with S-ICD use in patients in which a transvenous ICD is not a viable option. Methods 942 consecutive patients underwent S-ICD implantation at 22 Italian centers from 2014 to 2019. We identified 101 (11%) patients who received S-ICD because of the reported impossibility of deploying a transvenous lead. Results 21 patients presented with inadequate vascular access but no previous device in place. One patient had a mechanical prosthesis in tricuspid position. The remaining 79 patients received the S-ICD after removal of a prior system implanted, and venous occlusion was diagnosed after lead extraction, or partially or completely failed lead removal. In 24 of these patients a functional transvenous pacing system was left in place for persisting pacing needs. Patients were 60 ± 15 years old, 85% were male, 77% had ischemic or non-ischemic dilated cardiomyopathy, ejection fraction was 36 ± 13%. At implantation, acute conversion test was performed in 64 patients and shock energy of ≤65J was successful in 62 (96.9%) patients. During a median follow-up of 18 months, 6 patients died for non-device related reasons and 1 patient underwent heart transplantation. One patient underwent device replacement for battery depletion and one patient underwent leadless pacemaker implantation. Minor complications (hematomas not requiring system revision) were reported in 2 patients. Appropriate therapies were delivered in 4 patients and 8 patients experienced inappropriate therapies (in 3 patients due to double counting during pacing); all resolved with device reprogramming. Conclusions: In current clinical practice, a minority of S-ICD patients receive the device because of inadequate vascular access. The profile of these patients is similar to that of the typical ICD population in the context of primary sudden death prevention, but many of them present with pacing indications. Acute and mid-term efficacy of S-ICD seemed high. Few complications occurred during follow-up. Particular attention must be paid to device programming for those patients with concomitant pacing systems, in order to prevent inappropriate therapies.

Background. Atrial fibrillation (AF) is the most frequent sustained arrhythmia found in clinical practice. Its prevalence significantly grows with age. The proportion of elderly individuals with depression varies between 4.2 and 10.6% according to the different criteria used for diagnosis. Interestingly, AF and depression synergistically act to increase mortality. Purpose. Aim of this study was to identify the clinical variables associated with depressive symptoms in elderly individuals with persistent AF. Methods. All patients consecutively admitted in a Day-Hospital setting to undergo electrical cardioversion of AF were enrolled in the study. No exclusion criteria were specified. Population was studied with instruments exploring neurocognitive performance (Mini-Mental State Examination - MMSE; range: 0-30; abnormal values 5). In this case, lower scores identified a healthier emotional profile. Results. Between January 2018 and August 2019, 111 patients were evaluated (age: 77 ± 9 years; women: 39.6%; weight: 78 ± 15 Kg; height: 171 ± 11 cm). Lone AF and brady- tachy- syndrome were diagnosed in 12.6% of cases. Hypertension and structural heart disease (coronary artery disease, heart failure, valvular heart disease) were responsible of the arrhythmia in 30.6% and 56.8% of patients, respectively. Left ventricular ejection fraction was 60 ± 12%, with a heart rate equal to 78 ± 17 bpm. MMSE and SPPB score were 28 ± 3 and 8.7 ± 2.9. An abnormal GDS score was observed in 19.8% of cases (mean: 3.0 ± 2.7). Interestingly, in univariate analysis, depressive symptoms increased with age (p = 0.002) and the CHA2DS2-VASc score ( =6: 4.4 ± 2.8; p Conclusions. In a population of elderly patients with persistent AF, the prevalence of depression is not negligible. Importantly, depressive symptoms are significantly associated with the CHA2DS2-VASs score, and, at multivariate analysis, with renal function, to live alone and physical performance. Paradoxically, after adjustment for these factors, GDS score decreases with age per se.

Civil engineering structures and infrastructures are inherently vulnerable to exceptional loads related to natural disasters, primarily earthquakes, tsunamis, strong winds, and floods [...]

This contribution focuses on the design and the characterization of innovative mix designs of high consistency mortars with biochar additions in different percentage with respect to the cement weight. Biochar is a by-product material that gives the cementitious mix a sustainable connotation from an environmental point of view. The mix designs presented here are characterized by a good dimensional stability in the fresh state, peculiarity that gives them the possibility to be extruded and so, to be used in automated construction processes. In addition to the mechanical properties (flexural and compressive strength), the assessment of the CO2 emission of representative mixes is presented. Different biochar content and maximum diameter of the aggregate are studied, obtaining interesting indications on these parameters to optimize mechanical properties. Finally, on the basis of the CO2 emission assessment, certain venues for future research work to minimize CO2 emissions are reported.

Background Body mass index (BMI), age, left atrium (LA) dimension and left ventricular ejection fraction (LVEF) have been linked to post-operative atrial fibrillation (POAF) after cardiac surgery. The aim of this study was to better define the role of these risk factors. Methods This retrospective cohort study evaluated 249 patients (without prior atrial dysrhythmia) undergoing cardiac or aortic surgery. Prior to surgery, the following data were collected: age, BMI, LA diameter, LA area, LVEF, thyroid stimulating hormone (TSH), creatinine and the presence of arterial hypertension (AH) and diabetes. Intraoperative data such as operation time, total clamp time, cardiopulmonary bypass time, and presence of pericardial/pleural effusion were also collected. Only patients without pre- and post-surgery prophylactic anti-arrhythmic therapy were included. Results Patients with (N = 127, 51%) and without POAF (N = 122, 49%) were compared. No difference was observed for sex, LA diameter, LA area, LVEF, TSH, diabetes and use of ACE inhibitors or statins prior to intervention. Moreover, no difference was observed in terms of operation time, total clamp time, cardiopulmonary bypass time, and presence of pericardial/pleural effusion. However, patients with POAF were older (70.6 ± 10.7 vs. 60.4 ± 16.4 years, p = 0.001), had higher BMI (26.8 ± 4.5 vs. 24.9 ± 3.6 kg/m2, p = 0.001), higher baseline creatinine (1.06 ± 0.91 vs. 0.88 ± 0.32 mg/dL, p = 0.038) and a higher frequency of arterial hypertension (73.2% vs. 50%, p = 0.001) and Bentall procedure (24.4% vs. 9.8%, p = 0.023). Multivariate analysis showed that the only independent predictors of POAF were age (OR = 1.05, 95%CI 1.02–1.07, p = 0.001) and BMI (OR = 1.11 95%CI 1.03–1.2,p = 0.006). Conclusions These findings suggest that advanced age and a higher BMI are strong risk factors for POAF in patients without previous AF even in the presence of comparable LA dimensions and LVEF.

The present study concerns the experimental investigation of foamed concretes with 1600 kg/m3 density that incorporate biochar additions in the mix. A series of small notched beams are prepared to determine the fracture energy in CMOD (crack mouth opening displacement) mode and the mechanical properties in terms of flexural and compressive strength. Besides the evaluation of such properties for classical foamed concrete, the influence of the addition of biochar in the lightweight cementitious paste is comparatively investigated. Two different concentrations of biochar are analyzed, namely 2% and 4% of the cement weight, and two different curing conditions are studied, namely in air and in water at controlled temperature for 28 days. The results demonstrate that better fracture behavior are obtained with 2% biochar and air curing conditions. The biochar additions in moderate concentrations (e.g. 2%) seems to make the fracture surface more tortuous, thus justifying the numerical outcomes, and does not impair the flexural strength. Further microstructural investigation is underway to confirm the experimental observations. This research paves the way for a promising construction material that is more environmentally friendly and sustainable than traditional materials used in the building industry.

Unsatisfactory numerical predictions may result from applying the classical modal analysis in conjunction with the response-spectrum-method (RSM) to nonclassically-damped systems such as base-isolated buildings. This inaccuracy is highlighted by comparing the conventional RSM outcomes with results from nonlinear time-history analyses consistent with that given spectrum. Indeed, some underlying assumptions of the conventional RSM are not really appropriate for base-isolated buildings, thus only approximate results are obtained, whereas either a complex-value modal analysis or the direct integration of the equations of motion should be undertaken to follow an exact approach to this problem. In an attempt to overcome the limitations of the conventional RSM as well as the mathematical difficulties and computational cost of the exact approach, in this paper an improved response-spectrum analysis procedure for base-isolated buildings is elaborated. Based upon the substructure approach, this procedure makes use of novel response spectra that quantify the effects of the base-isolation-system (BIS) to the superstructure while accounting for the dynamic interaction between BIS and superstructure. The developed procedure improves the conventional RSM in two aspects: (1) the seismic response of the base-isolated building is computed by applying the modal analysis to the superstructure only, which is typically considered as a classically damped system, rather than to the overall structure having nonclassical damping; (2) the BIS can potentially be modeled as a nonlinear subsystem with its actual hysteretic characteristics. The effectiveness of the proposed procedure and the improvements over the conventional RSM are scrutinized against time-history analyses with Monte Carlo simulated spectrum-compatible accelerograms.

This review of the literature on the use of mechanical thrombectomy (MT) in children with acute ischemic stroke from occlusion of the internal carotid artery and the proximal middle cerebral artery (MCA) compares the efficacy and safety of primary and secondary MT. We analyzed the data reported for 24 case reports from 20 relevant articles published up to 31 December 2016 and the data of a patient treated at our institution. Eighteen cases received primary MT and 7 received secondary MT. The proportions of complete MCA recanalization, small infarcts, and asymptomatic intracranial hemorrhage were similar in both MT groups (73% [11/15] vs. 67% [4/6], 58% [7/12] vs. 60% [3/5], and 15% [2/13] vs. 17% [1/6], respectively). The proportion of favorable neurological outcomes was higher for the primary MT group (69% [11/16] vs. 43% [3/7]). We found no substantial differences in efficacy and safety between primary and secondary MT for anterior circulation stroke in children.

Existing civil engineering structures having strategic importance, such as hospitals, fire stations, and power plants, often do not comply with seismic standards in force today, as they were designed and built based on past structural guidelines. On the other hand, due to their special importance, structural integrity of such buildings is of vital importance during and after earthquakes, which puts demands on strategies for their seismic protection. In this regard, seismic base isolation has been widely employed; however, the existing limited seismic joint between adjacent buildings may hamper this application because of the large displacements concentrated at the isolation floor. In this paper, we compare two possible remedies: the former is to provide supplemental damping in conventional base isolation systems and the latter consists in a combination of base isolation with supplemental rotational inertia. For the second strategy, a mechanical device, called inerter, is arranged in series with spring and dashpot elements to form the so-called tuned-mass-damper-inerter (TMDI) directly connected to an isolation floor. Several advantages of this second system as compared to the first one are outlined, especially with regard to the limitation of floor accelerations and interstory drifts, which may be an issue for nonstructural elements and equipment, in addition to disturbing occupants. Once the optimal design of the TMDI is established, possible implementation of this system into existing structures is discussed.

In the field of stability of structures under nonconservative loads, the concept of follower force has long been debated by scientists due to the lack of actual experimental evidence. Bigoni and Noselli’s work [2] aimed to investigate flutter and divergence instability phenomena through a purely mechanical model with Coulomb friction represents a praiseworthy attempt to shed light on this issue. A two-degree-of-freedom (DOF) system, conceived as a variant of the Ziegler column, was set up experimentally. The follower load was induced by a frictional force acting on a wheel mounted at the column end, so that the rolling friction vanishes and the sliding frictional force keeps always coaxial to the column, thus representing a tangential follower force. Along this research line, in this contribution a model is elaborated that stems from the analysis of an elastically supported rigid plate that represents the behaviour of a bridge deck suspended on springs and subjected to a wind-induced force. The wind force has been simulated by a Coulomb friction force acting on a wheel mounted on the plate aerodynamic centre, so that the sliding friction force keeps perpendicular to the plate axis throughout the system motion, thus representing a follower force. To properly reproduce the wind force, the friction force is applied to the wheel by a lever mechanism wherein one of the two lever arms involves the plate rotation via a particular circular guide. The corresponding equations of motion of the bridge deck are derived in a completely dimensionless form. Depending on the mechanical characteristics of the plate and the magnitude of the friction force, stability, flutter or divergence phenomena may occur. The occurrence of these phenomena is numerically investigated by integration of the equations of motion. The development of an experimental framework of the model to corroborate these intuitions is the object of an ongoing research.

Background Atrial fibrillation (AF) is the most prevalent heart rhythm disorder in clinical practice and it is associated with poor quality of life and increased risks of heart failure, dementia, stroke, and death. Moreover AF management is a huge cost for healthcare systems. AF is irregular, typically originates from the pulmonary veins, and as such, requires cardioversion to terminate persistent episodes. AF is not susceptible to pace-termination, however, the MINERVA trial has shown that AF may transform in slower organized rhythms such as atrial flutter or atrial tachycardia, which can often be terminated by atrial anticahycardia pacing (ATP); in particular by Reactive ATP, a specific ATP feature which can be re-armed when atrial arrhythmias get slower or more regular. The MINERVA trial showed that the combination of ATP, preventive atrial pacing algorithms and minimal ventricular pacing (MVP) was associated with lower progression to persistent and permanent AF, compared with standard DDD pacing mode and to MVP mode, in pacemaker patients with clinical history of AF. Purpose We aimed to confirm MINERVA trial results in real-world clinical practice and to evaluate whether AF prevention was associated with preventive atrial pacing or solely with ATP. Indeed in our project atrial preventive pacing algorithms were not enabled and the pacing mode (DDD or MVP) was chosen according to patients' AV conduction characteristics. Methods Consecutive dual-chamber pacemaker patients with sinus node disease and device detected AT/AF were prospectively followed by 30 Italian cardiologic centers in an observational research. Clinical and device data were collected and reviewed by expert cardiologists to assess AT/AF occurrence through in clinic visit and/or remote transmissions of device data. Results A total of 239 patients (73 years old, 56% male) wearing a dual-chamber pacemaker with Reactive ATP were included in the project, followed for a median observation period of 13 months and compared with 1145 patients included in the MINERVA trial followed for a median observation period of 34 months and programmed with DDD pacing mode (383 patients), MVP (389 patients) and MVP+Reactive ATP+preventive algorithms (373 patients). As shown in the following figure incidence of 7 consecutive days of AF in the patients treated by DDD/MVP+Reactive ATP in real-world clinical practice was very similar to that found in the MINERVA trial arm programmed with MVP+Reactive ATP+preventive algorithms. Incidence of AF longer than 7 days Conclusions Our analysis performed in a population of sinus node disease patients with dual-chamber pacemakers confirmed MINERVA trial results in terms of prevention of long-lasting AF episodes. In particular these results confirm the benefit associated with the use of Reactive ATP, rather than preventive atrial pacing algorithms.

Background The benefit of cardiac resynchronization therapy (CRT) in patients (pts) with chronic kidney disease (CKD) remains controversial despite frequent use. Pts with impaired renal function have systematically been excluded from randomized clinical trials and therefore specific recommendations for the use of CRT in these pts are still lacking. Purpose Study objectives were to assess long-term outcomes and clinical/echocardiographic response in a large population of patients with moderate-to-severe impaired renal function implanted with a CRT device in accordance with the current standard of care. Methods We prospectively analyzed clinical, instrumental data and survival of pts with CKD who received a CRT device in the CRT-MORE registry from 2011 to 2014. Adverse events for the analysis of clinical outcome comprised death from any cause and nonfatal HF events requiring hospitalization after CRT implantation. LV reverse remodeling and Clinical Response (CR) were also evaluated at 12-month follow-up. Patients were stratified according to current definition of CKD stage: low-moderate CKD with a GFR = 45–59 mL/min (stage 3A); moderate CKD with a GFR = 30–44 mL/min (stage 3B) and severe CKD with a GFR = 15–29 mL/min (stage 4). Results Of the 922 consecutive patients enrolled in the registry, 416 (45%) pts had a moderate-to-severe impaired renal function (43% Stage 3A, 43% Stage 3B and 14% Stage 4). The mean follow-up was 935±506 days. By the end of the study, 85 pts had died and 47 pts had been hospitalized for HF. The combined end-point of death or HF hospitalization was reached by 121 (29%) pts. After 12 months the absolute LVEF improvement was greater than 10% in 37% of pts and 58% of pts displayed a positive clinical response. The percentage of pts who died was higher in the group of pts with severe CKD (32.8% vs 18.4%; p=0.012, compared to the group of pts with moderate CKD). On the contrary the percentage of pts who had at least one HF hospitalization was lower in the group with more severe CKD (2% vs 13%; p=0.011). According to CKD stage both LV remodeling (LVEF improvement ranging from 43.7% - 3A - to 30.8% - 4) and CR (positive response ranging from 63.9% - 3A - to 50% - 4) were higher in low-moderate stage and decreased with CKD severity. At multivariate Cox regression analysis adjusted for baseline confounders, CKD class at implantation [HR=1.5; 95% CI: 1.06–2.14; p=0.0219], chronic obstructive pulmonary disease [HR=1.89; 1.18–3.01; p=0.0077], persistent/permanent AF [HR=1.86; 1.15–3.01; p=0.0115] and male gender [HR=1.92; 1.07–3.46; p=0.0301] remained associated with death. Conclusions Among CKD patients in the CRT-MORE registry, severity of renal dysfunction at the time of CRT implantation was associated with worse prognosis, lower clinical response and LV reverse remodeling. Acknowledgement/Funding None

Background The frequency of premature atrial complexes (PACs) has been indirectly related with atrial fibrillation (AF) occurrence and adverse outcomes. Objective To evaluate whether temporal patterns of PACs are directly associated with AF onset in pacemaker patients with continuous monitoring of the atrial rhythm. Methods Overall, 193 pacemaker patients (49% female, 72±9 years old), enrolled in a national registry, were analyzed. Frequency of daily PACs was measured in a 14-day initial observation period, during which patients were in sinus rhythm. In the following period, temporal occurrence and frequency of daily PACs and eventual onset of AF were derived by pacemaker diagnostics. Results In the run-in period, median PACs frequency was 614 PACs/day (interquartile range=70–3056). Subsequently, in a median follow-up of 6 months, AF occurred in 109 patients, in particular in 37/96 (38.5%) patients with a PAC rate PACs changes daily trend before AF Conclusion PACs frequency increases in the 5–6 days preceding AF onset. A relative increase of the daily PACs is significantly associated with the risk of AF occurrence.