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Background: The risk of sudden cardiac death in patients with heart failure has declined over time thanks to the sequential introduction of new treatments. However, current guidelines recommendations for implantable cardioverter-defibrillator (ICD) are based on randomized controlled trials (RCTs) carried out in the past three decades and their meta-analyses. To highlight potential changes over time in ICD clinical benefit in primary prevention of sudden cardiac death, we analyzed the temporal trends of RCT risk of mortality outcomes in this time frame., Methods: By searching MEDLINE and the Cochrane Library electronic databases we identified seven RCTs (6095 patients enrolled between 1990 and 2014) on ICD versus contemporary standard medical therapy for sudden cardiac death prevention, in patients with chronic heart failure of ischemic and non-ischemic origin and reduced ejection fraction. Linear regression analysis was applied to identify the association between RCT mortality outcomes and time., Results: Ordered according to the start of randomization, the trials showed a statistically significant (p=0.03) progressive decline in the baseline annualized event rate of sudden cardiac death in RCT control arms, and a significant (p=0.04) increase in the number of patients unresponsive to ICD treatment (i.e. patients experiencing sudden cardiac death in ICD arms). These two factors synergistically contributed to a significant (p<0.01) and progressive reduction in the clinical benefit of ICD, assessed by the number needed to treat for total mortality at 3 years., Conclusions: The clinical benefit of ICD, implanted according to the current guidelines, has significantly and progressively declined over time due to the reduction in sudden cardiac death risk and to the increase of ICD unresponsive patients., (Copyright © 2019 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: Due to the growing epidemic of atrial fibrillation (AF), new strategies for AF screening, diagnosis, and monitoring are required. Wearable devices with on-board AF detection algorithms may improve early diagnosis and therapy outcomes. In this work, we implemented optimized algorithms for AF detection on a wearable ECG monitoring device and assessed their performance., Methods: The signal processing framework was composed of two main modules: 1) a QRS detector based on a finite state machine, and 2) an AF detector based on the Shannon entropy of the symbolic word series obtained from the instantaneous heart rate. The AF detector was optimized off-line by tuning its parameters to reduce the computational burden while preserving detection accuracy. On-board performance was assessed in terms of detection accuracy, memory usage, and computation time., Results: The on-board implementation of the QRS detector produced an overall accuracy of 99% on the MIT-BIH Arrhythmia Database, with memory usage = 672 bytes, and computation time ≤90 μs. The on-board implementation of the optimized AF algorithm gave an overall accuracy of 98.1% (versus 98.3% of the original version) on the MIT-BIH AF Database, with increased sensitivity (99.2% versus 98.5%) and decreased specificity (97.3% versus 98.2%), memory usage = 4648 bytes, and computation time ≤ 75 μs (consistent with real-time detection)., Conclusions: This study demonstrated the feasibility of real-time AF detection on a wearable ECG device. It constitutes a promising step towards the development of novel ECG monitoring systems to tackle the growing AF epidemic., Competing Interests: Declaration of competing interest Marsili IA, Biasiolli L, Adami A, and Andrighetti AO are with Medicaltech Srl, which developed the prototype device the algorithms were implemented on. Nollo G served as scientific advisor for Medicaltech srl., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Intraoral autologous bone grafting represents a preferential choice for alveolar reconstruction prior to dental implant placement. Bone block harvesting guided by a computer-planned lithographic template is a novel and promising technique for optimizing the volume of harvested material, while controlling the osteotomy 3D position with respect to delicate anatomical structures. We provide a quantitative framework to non-invasively estimate the accuracy of this technique. In the proposed framework, the planned osteotomy geometry was compared to the real outcome of the procedure, obtained by segmentation of post-procedural cone beam computed tomography data. The comparison required the rigid registration between pre and post-procedural mandibular models, which was automatically accomplished by minimizing the sum of squared distances via a stochastic multi-trial iterative closest point algorithm. Bone harvesting accuracy was quantified by calculating a set of angular and displacement errors between the planned and real planes which characterized the excision block. The application of the framework to four cases showed its capability to quantify the tolerance associated with computer-guided bone harvesting techniques with submillimetric accuracy (<0.4 mm), within the limits of native image resolution. The validation methodology proved suitable for defining the safety margins of osteotomy surgical planning., (Copyright © 2019. Published by Elsevier Ltd.)

Objectives: The authors performed a meta-analysis to evaluate the predictive value of late gadolinium enhancement (LGE) cardiac magnetic resonance for ventricular tachyarrhythmia in ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NICM) patients with ventricular dysfunction., Background: The use of LGE to detect myocardial fibrosis and its related arrhythmic substrate is well established. Several recent studies have described the predictive value of LGE for ventricular tachyarrhythmias; however, their validity is limited by small sample size and low number of events., Methods: MEDLINE and the Cochrane Library electronic databases were systematically searched to identify studies that applied LGE in ICM and NICM patients with ventricular dysfunction and reported arrhythmic clinical outcomes (sudden death, aborted sudden death, ventricular tachycardia, ventricular fibrillation, and appropriate implantable cardioverter-defibrillator [ICD] therapy, including antitachycardia pacing). A meta-analysis was performed to determine pooled odds ratios (ORs) for these arrhythmic events., Results: Nineteen studies that evaluated 2,850 patients with 423 arrhythmic events over a mean/median follow-up of 2.8 years were identified. The composite arrhythmic endpoint was reached in 23.9% of patients with a positive LGE test (annualized event rate of 8.6%) versus 4.9% of patients with a negative LGE test (annualized event rate of 1.7%; p < 0.0001). LGE correlated with arrhythmic events in the different patient groups. In the overall population, the pooled OR was 5.62 (95% confidence interval [CI]: 4.20 to 7.51), with no significant differences between ICM and NICM patients. In a subgroup of 11 studies (1,178 patients) with mean ejection fraction (EF) ≤30%, the pooled OR for the arrhythmic events increased to 9.56 (95% CI: 5.63 to 16.23), with a negative likelihood ratio of 0.13 (95% CI: 0.06 to 0.30)., Conclusions: LGE is a powerful predictor of ventricular arrhythmic risk in patients with ventricular dysfunction, irrespective of ICM and NICM etiology. The prognostic power of LGE is particularly strong in patients with severely depressed EF, which suggests its potential to improve patient selection for ICD implantation., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was computed as spectral power ratio (αBRS), non-causal transfer function gain (tfBRS) and causal transfer function gain (γBRS) evaluated at low frequency (0.04-0.14Hz) in the supine position (su) as well as in the standing upright position in the early tilt (et) and late tilt (lt) epochs. We found that, while αBRS decreased significantly in et and lt compared to su during all sessions, tfBRS and γBRS decreased during ASD and AMD but not during BD; moreover γBRS evidenced a progressive decrease from BD to ASD and to AMD in both et and lt epochs. These results indicate the necessity of following a causal approach for the estimation of BRS in the frequency domain, and suggest a progressive impairment of the baroreflex response to postural stress after single and multiple dives, which may reflect symptoms of increasing orthostatic intolerance., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objectives: The aim of this study was to investigate the anatomic distribution of critical sources in patients with atrial fibrillation (AF) by fusion of biatrial computed tomography (CT) images with cycle length (CL) and wave similarity (WS) maps., Background: Experimental and clinical studies show that atrial fibrillation (AF) may originate from rapid and repetitive (RR) sources of activation. Localization of RR sources may be crucial for an effective ablation treatment. Atrial electrograms showing rapid and repetitive activations can be identified by combining WS and CL analysis., Methods: Patients with persistent AF underwent biatrial electroanatomic mapping and pre-procedural CT cardiac imaging. WS and CL maps were constructed in 17 patients by calculating the degree of repetitiveness of activation waveforms (similarity index [S]) and the cycle length at each atrial site. WS/CL maps were then integrated with biatrial 3-dimensional CT reconstructions by a stochastic approach., Results: Repetitive sources of activation (S ≥ 0.5) were present in most patients with persistent AF (94%) and were mainly located at the pulmonary veins (82% of patients), at the superior caval vein (41%), on the anterior wall of the right atrium (23%), and at the left atrial appendage (23%). Potential driver sources showing both rapid and repetitive activations (CL = 140.7 ± 25.1 ms, S = 0.65 ± 0.15) were present only in a subset of patients (65%) and were confined to the pulmonary vein region (47% of patients) and left atrial appendage (12%). Differently, the repetitive activity of the superior caval vein was characterized by a slow activation rate (CL = 184.7 ± 14.6 ms)., Conclusions: The identification and localization of RR sources is feasible by fusion of biatrial anatomic images with WS/CL maps. Potential driver sources are present only in a subset of patients with persistent AF and are mainly located in the pulmonary vein region., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)