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The stochastic linearization technique (SLT), in its conventional force-based Gaussian version (FB-G-SLT), is widely adopted in the literature to handle the nonlinear power-law constitutive behavior of fluid viscous dampers (FVDs), either for evaluating the system response, or within optimal design strategies. In this note, the authors prove that, for the kind of nonlinearity induced by FVDs, this version of FB-G-SLT is not the best choice, especially if the velocity-related response is of major importance in an optimal design process. As an example, the energy dissipated by the devices depends upon the square of the velocity at the ends of the dampers. Among six different formulations of SLT examined in this note, an equal-energy non-Gaussian SLT (EE-NG-SLT) is found to be superior to the FB-G-SLT since it more satisfactorily captures the nonlinear response of the structure as predicted by Monte Carlo simulations. This alternative EE-NG-SLT, without requiring higher computational effort than the FB-G-SLT, is therefore recommended, especially when energy-based (or, in general, velocity-related) objective functions are used in the optimization problem of nonlinear viscous dampers.

The papers addresses a novel passive vibration control system combining seismic base isolation with a tuned inerter damper (TID) system. The latter, by analogy with the tuned mass damper (TMD), is a dynamic vibration absorber in which the physical mass of the TMD is partly or entirely replaced by an apparent mass, also called inertance, created by a particular arrangement of mechanical gearings—the inerter. By attaching a TID to the isolation floor, not only the displacement demand of base-isolated structures can be significantly reduced, but also the superstructure response (e.g. interstory drift, base shear) is effectively controlled. Optimum parameters of this system are found based on a simplified three degree-of-freedom model that reflects the dynamic properties of both the isolation system and the TID while accounting for the flexibility of the base-isolated superstructure. Within a probabilistic framework, the influence of soil conditions is investigated by modeling the seismic ground motion as a filtered Gaussian random process. Different filter parameters are considered that may be associated with firm, medium or soft soil conditions depending on the frequency content of the power spectral density function. A wide parametric study is performed in order to detect the optimal TID parameters depending on the soil conditions for a variety of isolation ratios, mass ratios and damping ratios of both the superstructure and the isolation system. Finally, a multi-story building equipped with the proposed passive vibration control system is examined. Effectiveness of the proposed system is assessed via the evaluation of the structural response in the time domain. Detuning effects are investigated via a sensitivity analysis. Comparison with alternative passive vibration control systems proposed in the literature and based on different arrangements of TMD and inerter-based device is discussed.

In the context of recycled concrete, the use of electric arc furnace (EAF) slag as partial or full replacement of coarse natural aggregates is particularly appealing because of the resulting economic and sustainability implications. Experimental investigation has been carried out on a set of reinforced concrete (RC) beams containing EAF slag as recycled aggregates under four-point bending tests. It has been found that the presence of steel slags leads to a higher flexural and shear capacity than the corresponding traditional RC beams, crack widths are reduced and the overall ductility is increased. Following these experimental findings, a numerical investigation is carried out. In particular, two different three-dimensional finite element procedures are adopted for comparative purposes against the experimental findings. The first procedure is a step-by-step incremental method based on a plasticity model for steel and a nonlinear stress-strain law for concrete in compression, while the post-failure behavior in tension is governed by a smeared-crack model. The second procedure is based on the limit analysis theory and permits one to simulate the limit state solution by carrying out simple elastic analyses in an iterative fashion. Comparison between numerical and experimental results is discussed and the main advantages and drawbacks of the two proposed numerical procedures are outlined.

Background Cardiac resynchronization therapy (CRT) nonresponse remains a major clinical problem. Autoantibodies specific for the β1-adrenergic (β1-AAbs) and muscarinic (M2-AAbs) receptors are found in patients with chronic heart failure (HF) of various etiologies. Materials and Methods We retrospectively analyzed 73 HF patients (median age 67 years, 84% males, New York Heart Association II–IV, in sinus rhythm, left ventricular ejection fraction 15% in left ventricular end-systolic volume at 6 months follow-up). Renal function (RF) parameters (creatinine [Cr], blood urea nitrogen [BUN], estimated glomerular filtration rate [eGFR Modified Diet in Renal Disease], cystatin C [Cys-C], and neutrophil gelatinase-associated lipocalin [NGAL]) were also evaluated. Results A significantly higher percentage of patients positive for β1-AAbs (OD sample/OD reference ratio >2.1) in nonresponders than in responder patients was observed (57% vs 27%, P = 0.004). No influence of M2-AAbs on CRT-D response was demonstrated. β1-AAbs were predictive of a poor CRT-D response (odds ratio [OR] [95% confidence interval (CI)] 3.64 [1.49–8.88], P = 0.005), also after adjustment for RF parameters (OR [95% CI] 4.95 [1.51–16.26], P = 0.008) observed to influence CRT-D response (Cr P = 0.03, BUN P = 0.009, Cys-C P = 0.02). The positive rates of β1-AABs in patients with abnormal blood level of Cr, eGFR, Cys-C, and NGAL were significantly higher than those with normal levels (P = 0.03, P = 0.02, P = 0.001, P = 0.007, respectively). Conclusions Our study suggests that (1) the evaluation of β1-AAb is useful to identify responders to CRT-D; (2) the presence of β1-AAbs is in relationship with elevated renal function parameters.

Background Cryoablation (CA) is an emerging tool for the treatment of supraventricular tachyarrhythmias. Determinants of long-term success still need clarification. Objective The purpose of this study was to assess which patients' and procedural features affect the long-term efficacy of CA for typical atrioventricular nodal reentrant tachycardia (AVNRT). Methods Eighty-five consecutive patients undergoing CA for typical AVNRT were divided into 3 groups of age: group A, ≤20 years, n=20 (23.5%); group B, 21–50 years, n=30 (35.3%); group C, ≥51 years, n=35 (41.2%). CA was performed for 5 minutes at −75°C in all; 4-minute bonus CA was delivered if not contraindicated (ie, transient PR interval lengthening during the first application and narrow triangle of Koch). The efficacy end point was the absence of recurrences at 12-month follow-up. Results CA was acutely successful in all 85 patients (100%). Bonus ablation was performed in 69 (81.2%). No permanent complications were observed. At follow-up, AVNRT recurrences occurred in 9 patients (10.6%): group A, 0 (0%); group B, 2 (6.7%), group C, 7 (20%). Incidence of recurrences was significantly different between age groups ( P = .047) and between patients receiving (7.2%) and not receiving (25.0%) bonus CA ( P = .038). In multivariable analysis, age groups (odds ratio [OR] 5.917; 95% confidence interval [CI] 1.372–25.518; P = .017) and bonus CA (OR 0.115; 95% CI 0.018–0.724; P = .021) were the only independent predictors of recurrences. Furthermore, age as a continuous variable remained statistically associated with recurrences (OR 1.046; 95% CI 1.002–1.091; P = .038). Conclusion CA is effective and safe for typical AVNRT ablation. Younger age and bonus CA administration are independent predictors of success at 12 months. Incidence of recurrences is low in patients younger than 21 years.

Introduction “Cardiac memory” (CM) refers to a change in repolarization induced by an altered pathway of activation, manifested after resumption of spontaneous ventricular activation (SVA). Aims To investigate for the first time in humans the effects of left ventricular (LV) pacing on CM development through vectorcardiography (VCG). Methods We studied 28 patients with heart failure (HF) and left bundle branch block (LBBB) treated with cardiac resynchronization therapy (CRT). Fourteen patients underwent biventricular (BIV) stimulation; the other 14 underwent LV stimulation only. VCG was acquired during SVA at baseline and during AAI and DDD pacing immediately after and 7 and 90 days after the implant. Results At baseline, in both groups, the QRS and T vectors angles were those specific of LBBB pattern. During DDD pacing, QRS vector angle changed to the right and upward in BIV patients while no significant differences were observed in LV patients. During AAI pacing, T vector angle changed significantly in BIV patients, following the direction of the paced QRS and amplitude significantly increased. In LV patients no significant differences in T vector angles were observed. Only T vector amplitude significantly increased at 7 days (p = 0.03) and at 90 days (p = 0.008 vs baseline). Conclusion In patients with LBBB, BIV pacing induces cardiac memory development as a significant change in T vector magnitude and angle, while LV pacing doesn’t induce significant modifications in QRS and T vector angles and CM is manifested only as a significant T vector amplitude change.

To evaluate failure probability of structures in the most general case is computationally demanding. The cost can be reduced by using the Response Surface Methodology, which builds a surrogate model of the target limit state function. In this paper authors consider a specific type of response surface, based on the Support Vector Method (SVM). Using the SVM the reliability problem is treated as a classification approach and extensive numerical experimentation has shown that each type of limit state can be adequately represented; however it could require a high number of sampling points. This work demonstrates that, by using a novel sampling strategy based on sampling directions, it is possible to obtain a good approximation of the limit state without high computational complexity. A second-order polynomial SVM model has been adopted, so the need of determining free parameters has been avoided. However, if needed, higher-order polynomial or Gaussian kernel can be adopted to approximate any kind of limit state. Some representative numerical examples show the accuracy and effectiveness of the presented procedure.

arterial coupling by reducing effective arterial elastance (Ea) on long-term follow-up. Detailed invasive studies showing possible acute peripheral effects of CRT are not available. We evaluated the hemodynamic effects of CRT in patients with systolic dysfunction, in order to investigate the impact on ventriculararterial coupling and, in particular, on Ea immediately after the initiation of pacing. Methods: We studied 37 heart failure patients undergoing CRT implantation based on conventional criteria. On implantation, left ventricular (LV) pressure and volume data were determined via a conductance catheter. Twelve patients with a standard indication for electrophysiologic study and preserved LV function served as a control group. Results: In comparison with the control group, heart failure patients showed reduced systolic and diastolic function. LV end-systolic elastance (Ees: end-systolic pressure/volume) was impaired (0.79 ± 0.33 mm Hg/mL vs 1.84 ± 0.89 mm Hg/mL, P = 0.012) and Ees/Ea reduced (0.36 ± 0.17 vs 1.19 ± 1.81, P = 0.022). In heart failure patients, CRT immediately improved systolic function, increasing stroke work from 3.9 ± 1.8 L*mm Hg to 6.9± 3.3 L*mm Hg (P< 0.001) and Ees to 1.02 ± 0.62 mm Hg/mL (P = 0.001). Ea decreased from 2.59 ± 1.35 mm Hg/mL to 1.68 ± 0.91 mm Hg/mL (P < 0.001), leading to an increase in Ees/Ea to 0.70 ± 0.38 (P < 0.001). Conclusion: Our data indicate that switching CRT on induces an immediate reduction in arterial load, conceivably as a consequence of restored autonomic balance. (PACE 2015; 00:1‐7)

The aim of the study was to evaluate the association between circulating (CPCs) and endothelial (EPCs) progenitor cells and left ventricular (LV) remodeling in chronic heart failure (HF). 85 HF patients, ranging 29–89 years, 83.5 % males, 45.9 % ischemic, NYHA functional class II–IV, with a LV ejection fraction ≤40 % were studied. LV ejection fraction, LV end-diastolic and end-systolic (LVESV) volumes, LV mass and tricuspid annular plane systolic excursion (TAPSE) were evaluated, and, when indicated, indexed for body surface area (BSA). CPCs and EPCs number was assessed using flow cytometry. CPCs were defined as CD34+, CD133+ and CD34+/CD133+. EPCs, identified through their expression of KDR, were defined as CD34+/KDR+, CD133+/KDR+ and CD34+/CD133+/KDR+. All EPCs were negatively related to LVESV/BSA (r = −0.24, p = 0.02 for all EPC’s populations), and to LVmass/BSA (CD34+KDR+; r = −0.30, p = 0.005; CD133+KDR+; r = −0.31, p = 0.004; CD34+CD133+KDR+; r = −0.29, p = 0.007). No differences in EPCs levels in relation to cardiovascular risk factors, medications, etiology, age or gender were observed. CPCs number was higher in women, and lower in ischemic patients. In logistic regression analyses, the low EPCs’ number was associated with an increased likelihood of abnormal LVmass/BSA. CPCs proved to be higher and EPCs lower in patients with severely abnormal LVmass/BSA (gr/m2, ≥122 in women and ≥149 in men). Our results suggest a correlation between LV remodeling and progenitor cells. This is noteworthy considering that it has been suggested that bone marrow-derived EPCs participate in cardiac regeneration and function recovery in the setting of progressive HF.

AIMS To investigate the different strategies adopted for the management of antithrombotic therapy and the related hemorrhagic and infective complication rates in patients undergoing cardiac implantable electronic devices (CIEDs) surgery in a real-world setting. METHODS THE Management of AntiThrOMbotic therApy in patients undergoing electrophysiological device surgery: Italian NatiOnal Multicenter Observational REgistry (HEMATOMA NO MORE) is an observational, prospective, multicenter, national cohort study (with a retrospective, multicenter, regional pilot phase) designed to enroll patients with standard indications to CIED implantations/replacements receiving concomitant antithrombotic therapy. The primary outcome is clinically significant pocket hematoma defined as a postprocedural hematoma, resulting in prolonged hospitalization and/or requiring interruption of antithrombotic therapy and/or requiring further surgery and/or requiring transfusion. RESULTS The pilot phase included 569 patients from 11 centers in Tuscany enrolled between September 2014 and May 2015 and followed up for 1 month. Patients were categorized according to the strategy of management of antithrombotic therapy, with heparin bridging being associated with the highest incidence of clinically significant pocket hematoma (12.3%). Overall nonpocket hemorrhagic events rate was quite low (0.52%) and thromboembolic complications were negligible (0.17%). CONCLUSION Occurrence of pocket hematoma in patients undergoing CIED surgery is largely influenced by the strategy of management of antithrombotic therapy. The HEMATOMA NO MORE will assess the impact of different strategies on the risk of developing pocket hematoma and of subsequent CIED-related infections.

Background: Although temporal lobe pathology may explain some of the symptoms of multiple sclerosis (MS), its role in the pathogenesis of seizures has not been clarified yet. Objectives: To investigate the role of temporal lobe damage in MS patients suffering from epilepsy, by the application of advanced multimodal 3T magnetic resonance imaging (MRI) analysis. Methods: A total of 23 relapsing remitting MS patients who had epileptic seizures (RRMS/E) and 23 disease duration matched RRMS patients without any history of seizures were enrolled. Each patient underwent advanced 3T MRI protocol specifically conceived to evaluate grey matter (GM) damage. This includes grey matter lesions (GMLs) identification, evaluation of regional cortical thickness and indices derived from the Neurite Orientation Dispersion and Density Imaging model. Results: Regional analysis revealed that in RRMS/E, the regions most affected by GMLs were the hippocampus (14.2%), the lateral temporal lobe (13.5%), the cingulate (10.0%) and the insula (8.4%). Cortical thinning and alteration of diffusion metrics were observed in several regions of temporal lobe, in insular cortex and in cingulate gyrus of RRMS/E compared to RRMS ( p< 0.05 for all comparisons). Conclusions: Compared to RRMS, RRMS/E showed more severe damage of temporal lobe, which exceeds what would be expected on the basis of the global GM damage observed.

Cryoablation (CA) emerged as an alternative procedure to radiofrequency (RF). The aim of this study was to compare haemostatic system alterations in patients undergoing RF or CA for atrioventricular nodal reentrant tachycardia ablation. von Willebrand factor (vWF), spontaneous whole blood platelet aggregation, prothrombin fragment F1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), plasminogen activator inhibitor type-1 (PAI-1), and clot lysis time (CLT) were determined in 48 patients (27 CA; 21 RF; 19M/29F, mean age 49.6 ± 17.6 years). Blood samples were obtained before the procedure (T0), immediately after (T1), and 24 h later (T2). At T1 both procedures were associated with a significant increase in levels of the endothelial activation marker vWF. At T2 vWF levels were lower in CA than in RF group. No changes in whole blood platelet aggregation before and after ablation procedures were observed. At T1 both groups determined an increase in blood clotting activation markers, F1 + 2, TAT, and DD. At T2 F1 + 2, TAT and DD levels were similar to baseline values. The comparison between RF and CA showed no significant differences in F1 + 2 and TAT levels, whereas at T1 DD levels were higher in CA group than in RF group. Both procedures induced a significant decrease in CLT, whereas no changes in PAI-1 levels were found. There were no significant differences in CLT and PAI-1 levels. The fibrinolytic efficiency analysis showed that at T1 DD/TAT and DD/F1 + 2 ratios were lower in RF group and remained lower in RF than in CA group at T2. CA procedure may be associated with a lower degree of endothelial damage and with a higher fibrinolytic capacity respect to RF.

Aims Metabolomic, a systematic study of metabolites, may be a useful tool in understanding the pathological processes that underlie the occurrence and progression of a disease. We hypothesized that metabolomic would be helpful in assessing a specific pattern in heart failure patients, also according to the underlining causes and in defining, prior to device implantation, the responder and nonresponder patient to cardiac resynchronization therapy (CRT). Methods In this prospective study, blood and urine samples were collected from 32 heart failure patients who underwent CRT. Clinical, electrocardiography and echocardiographic evaluation was performed in each patient before CRT and after 6 months of follow-up. Thirty-nine age and sex-matched healthy individuals were chosen as control group. For each sample, 1H-NMR spectra, Nuclear Overhauser Enhancement Spectroscopy, Carr-Purcell-Meiboom-Gill and diffusion edited spectra were measured. Results A different metabolomic fingerprint was demonstrated in heart failure patients compared to healthy controls with high accuracy level. Metabolomics fingerprint was similar between patients with ischemic and nonischemic dilated cardiomyopathy. At 6-month follow-up, metabolomic fingerprint was different from baseline. At follow-up, heart failure patients’ metabolomic fingerprint remained significantly different from that of healthy controls, and accuracy of cause discrimination remained low. Responders and nonresponders had a similar metabolic fingerprint at baseline and after 6 months of CRT. Conclusion It is possible to identify a metabolomic fingerprint characterizing heart failure patients candidate to CRT, it is independent of the different causes of the disease and it is not predictive of the response to CRT.

This contribution presents a set of experimental results on fiber-reinforced innovative lightweight panels (FRIL-panels) having thickness of 12mm. These panels are prepared with a peculiar foamed concrete that has a high viscosity and cohesion in the fresh state, which makes it particularly suitable for 3D printing applications. The FRIL-panels can be used for internal partitions, external infills, and suspended ceilings of buildings as more effective solutions than conventional plasterboard ones, with better thermal insulation and acoustic absorption properties due to the internal air-void microstructure. The aim of this work is to investigate the out-of-plane resistance of FRIL-panels, prepared with a density of 800kg/m3, under displacement-controlled three-point bending tests. In view of potential use in the precast industry, the FRIL-panels were placed into an accelerated concrete curing tank so as to speed up the overall production process. Modulus of rupture, ultimate deflection and collapse mode of FRIL-panels are critically analysed and discussed.

This contribution aims to highlight, from an experimental point of view, the key factors affecting the compressive strength of foamed concrete. An experimental campaign has been conducted on a broad group of cubic specimens made of foamed concrete under compression tests at 28 days. In addition to the obvious influence of the density on the achievement of the compressive strength, other factors have been studied. In particular, three different curing conditions, three foaming agents with either synthetic or protein nature, two different cement types, and three water/cement ratios have been included in this experimental investigation. As a result of this experimental campaign, it has been found that the not only the density, but also the foaming agent and the water/cement ratio play a major role in the strength achievement of the foamed concrete. It is also demonstrated that the combination of the foaming agent with a particular water/cement ratio is a crucial parameter affecting the compressive strength of this material.

Background Previous studies have reported that the left ventricular (LV) pacing site is a major determinant of the hemodynamic response to cardiac resynchronization therapy (CRT). However, lead positioning in a lateral or posterolateral cardiac vein may not be optimal for every patient. The objective of this study was to assess the relationship between the right ventricular (RV)-to-LV conduction time and the systolic function during CRT on the basis of changes to LV pressure-volume loops. Methods Left ventricular pressure and volume data were determined using a conductance catheter during CRT device implantation in 10 patients. Four endocardial LV sites were systematically assessed at four atrioventricular delays. The RV-to-LV conduction time was measured as the time interval between spontaneous peak R waves, recorded through the RV lead and the LV catheter. Results The optimal pacing site varied among patients. However, the pacing site associated with the maximum RV-to-LV conduction time resulted in a stroke volume improvement comparable to the pacing site identified through individual hemodynamic optimization (41 ± 17 mL vs 44 ± 18 mL, P = 0.266). Moreover, the RV-to-LV conduction time recorded at each endocardial pacing site correlated positively with the increase in stroke volume (r = 0.537; P < 0.001), stroke work (r = 0.642; P < 0.001), and the pressure-derivative maximum (r = 0.646; P < 0.001) obtained with CRT. Conclusions An optimal acute response to CRT can be obtained by positioning the LV lead at the site associated with the maximum RV-to-LV conduction time. A significant correlation appears to exist between RV-to-LV conduction time and the improvement in systolic function with CRT.

There have been substantial progresses in the technology of cardiac implantable electric devices (CIEDs) during the past decades. One of the progresses is represented by the development of a hemodynamic sensor embedded at the tip of a pacing lead that measures myocardial contractility by the analysis of myocardial mechanical vibrations occurring during the cardiac cycle. This sensor, providing continuous hemodynamic monitoring, could play an important role in clinical practice because of several clinical applications in CIEDs recipients. The objectives of this work are to report how this sensor operates and to review the main findings about its clinical applications.

Smoking is associated with increased morbidity and mortality in cardiac patients. However, data on the prognostic impact of smoking in heart failure (HF) patients on cardiac resynchronization therapy with defibrillator (CRT-D) are absent. We investigated the effects of smoking on all-cause mortality and on a composite endpoint (all-cause death/appropriate device therapy), appropriate and inappropriate device therapy, in 649 patients with HF who underwent CRT-D between January 2003 and October 2011 in 6 Centers (4 in Italy and 2 in USA). 68 patients were current smokers, 396 previous-smokers (patients who had smoked in the past but who had quit before the CRT-D implant), and 185 had never smoked. The risk of each endpoint by smoking status was evaluated with both Kaplan–Meier and Cox proportional-hazard analysis. After adjusting for age, left ventricular ejection fraction, QRS width and ischemic etiology, both current and previous smoking were independent predictors of all-cause death [HR = 5.07 (95 % CI 2.68–9.58), p

Recurrences within the blanking period (early recurrences) are common after atrial fibrillation (AF) ablation by pulmonary vein isolation (PVI), but their clinical significance is still controversial. We aimed at evaluating the significance of within-blanking recurrences at 12-month follow-up after cryoballoon (CB) PVI, and to assess the real procedural success rate by continuous monitoring of cardiac rhythm.Sixty consecutive AF patients (34 paroxysmal, 56.7%) underwent their first CB-PVI at one Italian center (May 2013 to April 2015), and subsequent implantation of an implantable loop recorder (ILR). Overall, 12-month success rate after the blanking period was 55%. The shortest detected event was 7 minutes long. Late recurrences were more frequent in non-paroxysmal (19/26, 73.1%) than in paroxysmal AF (8/34, 23.5%; P0.001). Early recurrences occurred in 17 (28.3%) patients, with 14 also having late recurrences (82.3%), while only 13 out of 43 (30.2%) without within-blanking recurrences experienced post-blanking events (P0.001). Overall, early recurrences showed 51.8% sensitivity (95% CI 31.9-71.3%) and 90.9% specificity (95% CI 75.7-98.1%) for later recurrences, with 82.3% (95% CI 56.6-96.2%) positive and 69.8% (95% CI 53.9-82.8%) negative predictive value. The positive likelihood ratio was 5.7 (95% CI 1.8-17.8). At multivariable analysis, non-paroxysmal AF (HR: 3.113; 95% CI 1.309-7.403; P = 0.010) and within-blanking recurrences (HR: 3.453; 95% CI 1.544-7.722; P = 0.003) were independent predictors of post-blanking AT/AF.CB-PVI for paroxysmal AF shows a 12-month success rate of 76.5% after one single procedure, as assessed by continuous cardiac rhythm monitoring. Within-blanking recurrences predict the ablation failure in more than 80% of patients.

This review will focus on the feasibility of long term His bundle pacing and its effects on left ventricle (LV) hemodynamics. Compared with right ventricular pacing, His bundle pacing results in a more physiological electro-mechanical activation that contributes to preserve LV function. Moreover some studies showed a similar effect to biventricular pacing in patients with heart failure and left bundle branch block. Recent observations indicate that His bundle pacing should be considered as an optimal site to pace right ventricle in patients who are candidates for cardiac resynchronization therapy.

This paper enriches the statistical moment-based damage detection method with approximate parametric solutions of the stationary second-order moments of nodal displacements and velocity, which are explicitly related to stiffness and modal damping parameters. Then, a weighted least-squares approach is employed to search for the stiffness and damping inversely when the objective function is minimized. The method is able to detect both stiffness reduction, simulating damage, and modal damping ratio of relevant modes, the latter being a decisive issue for damage detection. After the procedure to get an approximate explicit solution is recalled, the steps involved in the identification process are stated and an eventual modal truncation is proposed to allow the analysis of larger systems. Applications on a pinned beam and a two-dimensional panel are reported to check the consistency of the method and to investigate to effects of measurement noise on the identification procedure.

Background— Previous studies have investigated the role of intrinsic conduction in optimizing cardiac resynchronization therapy. We investigated the role of fusing pacing-induced activation and intrinsic conduction in cardiac resynchronization therapy by evaluating the acute hemodynamic effects of simultaneous His-bundle (HIS) and left ventricular (LV) pacing. Methods and Results— We studied 11 patients with systolic heart failure and left bundle-branch block scheduled for cardiac resynchronization therapy implantation. On implantation, LV pressure–volume data were determined via conductance catheter. Standard leads were placed in the right atrium, at the right ventricular apex, and in a coronary vein. An additional electrode was temporarily positioned in the HIS. The following pacing configurations were systematically assessed: standard biventricular (right ventricular apex+LV), LV-only, HIS, simultaneous HIS and LV (HIS+LV). Each configuration was compared with the AAI mode at multiple atrioventricular delays (AVD). In comparison with the AAI, right ventricular apex+LV and LV-only pacing resulted in improved stroke volume (85±32 mL and 86±33 mL versus 58±23 mL; P 76 mL at all fixed intervals and 88±31 mL at optimal interval; all P Conclusions— Standard right ventricular apex+LV and LV-only pacing enhanced systolic function and LV synchrony at individually optimized AVD close to the measured intrinsic P-H interval. By contrast, HIS+LV pacing yielded improvements, regardless of AVD setting. These findings support the hypothesis of the crucial role of intrinsic right ventricular conduction in optimal cardiac resynchronization therapy delivery.

Aims The haemodynamic SonR sensor is able to measure myocardial contractility. The isometric effort is useful in quantifying left ventricular (LV) performance. We investigated the amplitude changes in SonR signal over time and during static exercise according to the recovery of the left ventricle. Methods and results Twenty five patients [18 male, 70 ± 8 years, LV ejection fraction (LVEF) 29 ± 5%, in sinus rhythm] underwent biventricular SonR implantable cardioverter defibrillator implant. After procedure and at 6 months, each patient underwent detection of SonR signal and continuous measurement of blood pressure, at rest and during isometric effort. During evaluation at baseline device was programmed in VVI at 40 bpm while in DDD at 60 bpm at follow-up. At 6 months, LV reverse remodelling was investigated. Cardiac resynchronization therapy patients were considered responders when an absolute improvement in LV ejection fraction ≥ 5% occurred. At 6 months, 14 (56%) patients were responders and 11 (44%) non-responders (mean LVEF 40 ± 10% vs. 27 ± 6%, respectively). In responders, SonR value did not significantly change at follow-up compared to baseline ( P = 0.894). At follow-up, SonR value was not significantly different between two groups ( P = 0.651). SonR signal significantly increased during isometric effort in responders ( P = 0.002) while it slightly decreased in non-responders at follow-up ( P = 0.572). No differences were observed in response to isometric effort between two groups at baseline ( P = 0.182, P = 0.069, respectively). Conclusions The absolute SonR amplitude provides limited information on the status of LV performance. The variation in SonR signal during static exercise is more likely to identify responders at follow-up.

Purpose The paper illustrates a viaduct collapse due to corrosion phenomena. Moreover, a contribution to the issues related to both the control of existing structures and design methods to be followed for the construction of new buildings is provided. Design/methodology/approach The objectives were achieved by in situ observations and numerical analyses. The effects of corrosion phenomena are investigated, and the progressive collapse analysis is provided to be helpful in this case. Findings The damages induced by corrosion phenomena have caused the collapse of the viaduct taken in to account. The performed numerical analyses were able to reproduce the effects of corrosion in terms of reduction of wires diameter. Research limitations/implications The research is limited to prestressed concrete viaduct with post-tensioned cables. Practical implications A monitoring plan, subdivided in several phases, is suggested, to avoid critical situations as these described. Originality/value The case study brought useful information on the effects of corrosion on the decks section, showing how the technology in post-tensioned cables is usually insidious and prone to the issues relating to corrosion of the wires

Cardiac resynchronization therapy (CRT) nonresponse remains a major clinical problem. Autoantibodies specific for the β1-adrenergic (β1-AAbs) and muscarinic (M2-AAbs) receptors are found in patients with chronic heart failure (HF) of various etiologies.We retrospectively analyzed 73 HF patients (median age 67 years, 84% males, New York Heart Association II-IV, in sinus rhythm, left ventricular ejection fraction35%) who received CRT defibrillator (CRT-D) from 2010 to 2013. β1-AAbs and M2-AAbs were measured by enzyme-linked immunosorbent assay. Echocardiography was used to assess CRT response (reduction15% in left ventricular end-systolic volume at 6 months follow-up). Renal function (RF) parameters (creatinine [Cr], blood urea nitrogen [BUN], estimated glomerular filtration rate [eGFR Modified Diet in Renal Disease], cystatin C [Cys-C], and neutrophil gelatinase-associated lipocalin [NGAL]) were also evaluated.A significantly higher percentage of patients positive for β1-AAbs (OD sample/OD reference ratio2.1) in nonresponders than in responder patients was observed (57% vs 27%, P = 0.004). No influence of M2-AAbs on CRT-D response was demonstrated. β1-AAbs were predictive of a poor CRT-D response (odds ratio [OR] [95% confidence interval (CI)] 3.64 [1.49-8.88], P = 0.005), also after adjustment for RF parameters (OR [95% CI] 4.95 [1.51-16.26], P = 0.008) observed to influence CRT-D response (Cr P = 0.03, BUN P = 0.009, Cys-C P = 0.02). The positive rates of β1-AABs in patients with abnormal blood level of Cr, eGFR, Cys-C, and NGAL were significantly higher than those with normal levels (P = 0.03, P = 0.02, P = 0.001, P = 0.007, respectively).Our study suggests that (1) the evaluation of β1-AAb is useful to identify responders to CRT-D; (2) the presence of β1-AAbs is in relationship with elevated renal function parameters.

Spontaneous behavior of ventricular extrasystoles (VE) was analysed. From a database containing 578 athletes with VE, 84 males and 11 females (29.9 ± 18.1 years) having ≥ 100 VE or repetitive VE [ventricular couplets (VC) or ventricular tachycardias (VT)] at first 24-hour Holter electrocardiographic monitoring (24-h-HM) (baseline) and at least 1-year of follow-up (3.1 ± 2.2 years) over the past 10 years were selected. The baseline was compared with the last 24-h-HM to establish DVE (VE reduction of at least 98%/24 h in the absence of VC or VT). SDVE was calculated as standard deviation of the number of VE on serial 24-h-HMs. DVE and SDVE were considered as dependent variables. Independent variables were: age, sex, type of sport, symptoms, baseline VE rate (BVE), baseline VC and VT, VE morphology, VE behavior during the baseline training session, disqualification from competitive sports, echocardiographic abnormalities. DVE occurred in 32 athletes (34%). SDVE varied from 0 to 12,658 VE/24 h (1916 ± 2649.9). Disappearance of VE during the baseline training session (DVET) correlated to DVE (P = 0.0319). BVE directly correlated to SDVE (P = 0.0008). Athletes' VE are highly variable over time, their variability depending on BVE, and they not infrequently tend to disappear. The only useful variable for predicting DVE is DVET.

Aims The aims of the study are to develop a cost-minimization analysis from the hospital perspective and a cost-effectiveness analysis from the third payer standpoint, based on direct estimates of costs and QOL associated with remote follow-ups, using Merlin@home and Merlin.net, compared with standard ambulatory follow-ups, in the management of ICD and CRT-D recipients. Methods and results Remote monitoring systems can replace ambulatory follow-ups, sparing human and economic resources, and increasing patient safety. TARIFF is a prospective, controlled, observational study aimed at measuring the direct and indirect costs and quality of life (QOL) of all participants by a 1-year economic evaluation. A detailed set of hospitalized and ambulatory healthcare costs and losses of productivity that could be directly influenced by the different means of follow-ups will be collected. The study consists of two phases, each including 100 patients, to measure the economic resources consumed during the first phase, associated with standard ambulatory follow-ups, vs. the second phase, associated with remote follow-ups. Conclusion Remote monitoring systems enable caregivers to better ensure patient safety and the healthcare to limit costs. TARIFF will allow defining the economic value of remote ICD follow-ups for Italian hospitals, third payers, and patients. The TARIFF study, based on a cost-minimization analysis, directly comparing remote follow-up with standard ambulatory visits, will validate the cost effectiveness of the Merlin.net technology, and define a proper reimbursement schedule applicable for the Italian healthcare system. Trial registration: NCT01075516.

Background: The Seattle Heart Failure Model (SHFM) is a multimarker risk assessment tool able to predict outcome in heart failure (HF) patients. Aim: To assess whether the SHFM can be used to risk-stratify HF patients who underwent cardiac resynchronization therapy with (CRT-D) or without (CRT) an implantable defibrillator. Methods and Results: The SHFM was applied to 342 New York Heart Association class III-IV patients who received a CRT (23%) or CRT-D (77%) device. Discrimination and calibration of SHFM were evaluated through c-statistics and Hosmer-Lemeshow (H-L) goodness-of-fit test. Primary endpoint was a composite of death from any cause/cardiac transplantation. During a median follow-up of 24 months (25th–75th percentile [pct]: 12–37 months), 78 of 342 (22.8%) patients died; seven patients underwent urgent transplantation. Median SHFM score for patients with endpoint was 5.8 years (25th–75th pct: 4.25–8.7 years) versus 8.9 years (25th–75th pct: 6.6–11.8 years) for those without (P < 0.001). Discrimination of SHFM was adequate for the endpoint (c-statistic always ranged around 0.7). The SHFM was a good fit of death from any cause/cardiac transplantation, without significant differences between observed and SHFM-predicted survival. Conclusion: The SHFM successfully stratifies HF patients on CRT/CRT-D and can be reliably applied to help clinicians in predicting survival in this clinical setting. (PACE 2012; 35:88–94)

Aims Functional mitral regurgitation (MR) could be managed by both cardiac resynchronization therapy (CRT) and mitral-valve surgery. Clinical decision making regarding the appropriateness of mitral-valve surgery vs. CRT is a challenging task. This study assessed the prevalence and prognosis of various degrees of functional MR in CRT candidates. Additionally, we sought to identify functional MR patients who either can be adequately managed by CRT only or will need surgery. Methods and results Cardiac resynchronization therapy recipients ( n = 794) were followed-up for 26 ± 18 months. Mitral regurgitation severity was quantified on scale 0–4. Cardiac resynchronization therapy responders were identified based on improvement in the New York Heart Association class and left-ventricular ejection fraction. Severity of MR and LV reverse remodelling were assessed at 3 and 12 months. Predictors of long-term MR change and CRT response were explored with multivariable models. Mitral regurgitation was present in 86%, with 35% prevalence of advanced MR (grade 3–4). Improvement of MR ≥1° after 12 months occurred in 46% of patients. It was relatively more frequent in patients with advanced MR at baseline (63%, P < 0.01). Baseline MR severity and change in MR at 3-month follow-up predicted response to CRT. Patients with ≥1° MR improvement at 12 months had more reverse remodelling compared with those with no change or worsening of MR. Conclusions Mitral regurgitation improvement at 3 months predicts CRT response and MR improvement at 12-month follow-up. This finding could have implications for subsequent MR surgical therapies.

Background: The management of implantable cardioverter defibrillators (ICDs) affected by advisories, which often include generator replacement, is complex and the risk of device failure needs to be carefully assessed for each patient. Methods: We analyzed the response to the advisory communication in the Italian centers involved in the recall for the Prizm 1861 and Renewal (Boston Scientific–formerly Guidant—St. Paul, MN, USA) communication. Results: One hundred and thirty-nine of 843 Prizm (16.5%) and 458 of 2,342 Renewal devices (19.6%) were explanted. The total incidence over a 4-year time frame of the failure event was equal to zero of 710 (0%) for Prizm ICDs and eight of 2,342 (0.34%) for Renewal ICDs. A limited percentage of devices affected by recall were definitely explanted following the indications stated by the advisory. The failure rates that resulted from analysis of our data (0% for Prizm and 0.34% for Renewal) were inferior to those already found or projected along the device lifetime globally, as reported in the most recent Company Product Performance Report (0.72% for Prizm and 1.83% for Renewal). Conclusions: In absence of underestimation of the events, a lower incidence than expected could resize the dimension of the problem, justifying the concept of a more frequent follow-up of patient with respect to the choice of an immediate device explant. (PACE 2011; 34:998–1002)

Delineation of clinical target volume (CTV) is still controversial in glioblastomas. In order to assess the differences in volume and shape of the radiotherapy target, the use of pre-operative vs post-operative/pre-radiotherapy T(1) and T(2) weighted MRI was compared.4 CTVs were delineated in 24 patients pre-operatively and post-operatively using T(1) contrast-enhanced (T1(PRE)CTV and T1(POST)CTV) and T(2) weighted images (T2(PRE)CTV and T2(POST)CTV). Pre-operative MRI examinations were performed the day before surgery, whereas post-operative examinations were acquired 1 month after surgery and before chemoradiation. A concordance index (CI) was defined as the ratio between the overlapping and composite volumes.The volumes of T1(PRE)CTV and T1(POST)CTV were not statistically different (248 ± 88 vs 254 ± 101), although volume differences100 cm(3) were observed in 6 out of 24 patients. A marked increase due to tumour progression was shown in three patients. Three patients showed a decrease because of a reduced mass effect. A significant reduction occurred between pre-operative and post-operative T(2) volumes (139 ± 68 vs 78 ± 59). Lack of concordance was observed between T1(PRE)CTV and T1(POST)CTV (CI = 0.67 ± 0.09), T2(PRE)CTV and T2(POST)CTV (CI = 0.39 ± 0.20) and comparing the portion of the T1(PRE)CTV and T1(POST)CTV not covered by that defined on T2(PRE)CTV images (CI = 0.45 ± 0.16 and 0.44 ± 0.17, respectively).Using T(2) MRI, huge variations can be observed in peritumoural oedema, which are probably due to steroid treatment. Using T(1) MRI, brain shifts after surgery and possible progressive enhancing lesions produce substantial differences in CTVs. Our data support the use of post-operative/pre-radiotherapy T(1) weighted MRI for planning purposes.

"Cardiac memory" (CM) refers to a change in repolarization induced by an altered pathway of activation. The effects of biventricular pacing on CM induction have not been investigated.To investigate the development of CM during cardiac resynchronization therapy (CRT) through vectorcardiography (VCG).Eleven patients undergoing CRT were enrolled. VCG was acquired during spontaneous ventricular activation at baseline and during AAI and DDD pacing immediately after and 7, 14, 21 and 60 days after the implantation.At 1-week follow-up, during AAI pacing T vector angles significantly changed (azimuth 23 ± 19°; p = 0.002; elevation 23 ± 27°; p = 0.019) and magnitude significantly increased (baseline 1.13 ± 0.69 mV; 7 days: 1.77 ± 1.27 mV; p = 0.026). T angle changes remained stable throughout the follow-up period while a further significant increase in magnitude was observed at 60 days (2.21 ± 1.50 mV; p = 0.01 vs. baseline and p = 0.04 vs. 7 days). Paced T vector magnitude at implant (2.24 ± 1.25 mV) decreased significantly at 7 days (1.64 ± 1.26 mV; p = 0.030) with a further significant decrease at 60 days (1.40 ± 1.18 mV; p = 0.003 vs. baseline; p = 0.02 vs. 7 days).CRT induces a significant change in T vector magnitude, azimuth, and elevation after resumption of spontaneous ventricular activation after 7 days from implantation. While further changes in T vector angle were not observed, after 2 months of CRT a significant decrease of paced T vector magnitude and a significant increase of spontaneous T vector magnitude were observed.

Background: Sleep disordered breathing (SDB), a common condition among patients with permanent pacemaker (PM), is associated with greater incidence of cardiac arrhythmias. Scarce availability of sleep laboratories and the high costs of nocturnal-attended polysomnography limit the routine screening of patients with PM for SDB. We investigated whether a novel PM that utilizes variations in transthoracic impedance to record the fluctuations in breathing pattern and minute ventilation could be used to screen patients for SDB. Methods: Twenty patients who underwent dual-chamber PM implantation were studied. The Talent 3 DR PM (SORIN Group Italy S.r.l., Milan, Italy) calculates apnea-hypopnea index (AHI) by computing minute ventilation signal derived from transthoracic impedance measurements. Within a month after PM implantation, an in-home respiratory monitoring was performed to evaluate the accuracy of PM-derived AHI. Patients were followed for mean ± standard deviation, 487 ± 166 days. The PM was checked at each follow-up visit to retrieve the information about recurrent arrhythmias. Results: Eleven patients were diagnosed with SDB by an in-home respiratory monitoring. An AHI derived from an in-home respiratory monitoring was similar to pacemaker-derived AHI (27 ± 14 vs 16 ± 13 events/hour, P = 0.15). The cumulative incidence of cardiac arrhythmias, including atrial fibrillation, extrasystolic beats, sustained and nonsustained ventricular tachycardia, and supraventricular tachycardia was similar in patients with and without SDB. Conclusion: SDB is highly prevalent in patients with permanent pacemaker. Screening for SDB with Talent 3 DR PM may facilitate diagnosis and treatment of SDB. (PACE 2010; 33:1462–1466)

AIM We evaluated the predictive value of echo/Doppler derived indices, which reflect the duration of the isovolumic phases of the cardiac cycle, in identifying cardiac resynchronization therapy (CRT) responders. METHODS AND RESULTS In 105 patients before and 6 months after CRT the following echo/Doppler parameters were evaluated: myocardial performance index (MPI) as the sum of isovolumic contraction time (IVCT) and isovolumic relaxation time (IVRT) divided by ejection time; total isovolumic time (t-IVT) as the sum of IVCT and IVRT divided by the RR interval; and standard deviation of the time to systolic peak velocity (Ts-SD) as asynchrony index. After 6 months, patients were defined responders according to 15% left ventricle (LV) end-systolic volume reduction or more. At baseline, responders (53.3%) had higher t-IVT and MPI than nonresponders (0.30 +/- 0.06 versus 0.22 +/- 0.05, P < 0.0001 and 1.01 +/- 0.27 versus 0.73 +/- 0.19, P < 0.0001, respectively). Receiving operating characteristic curve analysis showed that both t-IVT (80.3% sensitivity and 83.7% specificity, cut-off = 0.263) and MPI (78.6% sensitivity and 81.6% specificity, cut-off = 0.84) could predict CRT response. Baseline t-IVT correlated well to end-systolic volume reduction (r = -0.56, P < 0.00001). CONCLUSION Echo/Doppler derived indices, describing physiologic abnormalities of the isovolumic contraction and relaxation phase, are able to predict CRT-induced reverse remodeling.

Although it is established that Alzheimer's disease (AD) leads to cerebral macrostructural atrophy, microstructural diffusion changes have also been observed, but it is not yet known whether these changes offer unique information about the disease pathology. Thus, a multi-modal imaging study was conducted to determine the independent contribution of each modality in moderate to severe AD. Seventeen patients with moderate-severe AD and 13 healthy volunteers underwent diffusion-weighted and T1-weighted MR scanning. Images were processed to obtain measures of macrostructural atrophy (gray and white matter volumes) and microstructural damage (fractional anisotropy and mean diffusivity). Microstructural diffusion changes independent of macrostructural loss were investigated using an ANCOVA where macrostructural maps were used as voxel-wise covariates. The reverse ANCOVA model was also assessed, where macrostructural loss was the dependent variable and microstructural diffusion tensor imaging maps were the imaging covariates. Diffusion differences between patients and controls were observed after controlling for volumetric differences in medial temporal, retrosplenial regions, anterior commissure, corona radiata, internal capsule, thalamus, corticopontine tracts, cerebral peduncle, striatum, and precentral gyrus. Independent volumetric differences were observed in the entorhinal cortex, inferior temporal lobe, posterior cingulate cortex, splenium and cerebellum. While it is well known that AD is associated with pronounced volumetric change, this study suggests that measures of microstructure provide unique information not obtainable with volumetric mapping in regions known to be pivotal in AD and in those thought to be spared. As such this work provides great understanding of the topography of pathological changes in AD that can be captured with imaging.

An efficient procedure for the reliability analysis of frame structures with respect to the buckling limit state is proposed under the assumption that no imperfections are present and that the elastic parameters are uncertain and modeled as random variables. The approach allows a deeper investigation of structures which are not sensitive to imperfections. The procedure relies on a Response Surface Method adopting simple ratio of polynomials without cross-terms as performance function. Such a relationship approximates analytically the dependence between the buckling load and the basic variables furnishing a limit state equation which is very close to the exact one when a proper experimental design is adopted. In this way a Monte Carlo Simulation applied to the response surface leads to a good approximation with low computational effort. Several numerical examples show the accuracy and effectiveness of the method varying structural complexity, correlation between basic variables and their distribution.

The medical device industry must implement accurate programs to monitor product performance once the product is released into the market. Product-experience reports provide a means for physicians who use medical devices to provide continuous feedback to manufacturers in order to monitor device performance. We examined product-experience reports sent from Italy over 4 years (2004-2007) related to a single manufacturer's family of permanent endocardial leads (Endotak Reliance, Boston Scientific, MA, USA) used with implantable cardioverter-defibrillators. Out of 15,772 implanted leads, physicians sent in 454 (2.87%) product-experience reports. Only 126 out of 454 (28%) leads were returned to the company; most of these (101 out of 126; 80%) were related to implant procedure. Laboratory analyses of returned leads rarely showed loss of integrity (0.01%). The practice of reporting product performance and returning the device to companies should be strongly encouraged in order to better identify potential issues affecting implantable devices.

The detection and classification of hepatic vessels in diagnostic images are essential for hepatic pre-surgery planning. Our team has developed a tool for classification, analysis, and 3D reconstruction of the hepatic and portal systems. Our software first extracts a graphic representation of a set of connected voxels, representing both systems. It then calculates two binary volumes representing the main part of the two venous systems. Finally, it combines these results to obtain the correct vessel classification. Segmentation steps are semi-automatic and require about 40 min to complete. Schematization and classification steps are automatic and require about 17 min for results. The software provides a correct and detailed reconstruction even where pathologies have caused morphological and geometrical variations in the vessels. The time required for the entire procedure is compatible with clinical requirements, providing an efficient tool for diagnosis and surgical planning.