Onset of Ventricular Arrhythmias in Ischemic and Non-Ischemic Cardiomyopathies

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The Web will kill them all: new media, digital utopia, and political struggle in the Italian 5-Star Movement

This article examines the role of discourses about new media technology and the Web in the rise of the 5-Star Movement (Movimento 5 Stelle, or M5S) in Italy. Founded by comedian and activist Beppe Grillo and Web entrepreneur Gianrobe rto Casaleggio in 2009, this movement succeeded in becoming the second largest party at t he 2013 national elections in Italy. This article aims to discuss how elements of digital uto pia and Web-centric discourses have been inserted into the movement’s political message, and how the construction of the Web as a myth has shaped the movement’s discourse and political p ractice. The 5-Star Movement is compared and contrasted with other social and political move ments in Western countries which have displayed a similar emphasis on new media, such as the Occupy movement, the Indignados movement, and the Pirate Parties in Sweden and Germ any. By adopting and mutating cyber- utopian discourses from the so-called Californian i deology, the movement symbolically identifies itself with the Web. The traditional political esta blishment is associated with “old” media (television, radio, and the printed press), and rep resented as a “walking dead,” doomed to be superseded and buried by a Web-based direct democra cy

Computationally inexpensive methods for intra-cardiac atrial bipolar electrogram compression

Aim. This paper reports studies of mathematical algorithms for intra-cardiac atrial bipolar electrogram compression suitable with implementation on implantable devices. Patients and Methods. Bipolar intra-cardiac electrograms (IEGMs) of high right atrium were obtained from 20 patients who underwent electrophysiological studies for arrhythmias. Four thousand seven hundred and eighty-two seconds of IEGM were collected and divided into three rhythm groups: sinus rhythm (SR), atrial fibrillation (AF) and atrial flutter (AFL). Since mathematical algorithms suitable for use with implantable devices demand low computational cost, we employed piecemeal linear approximation methods (ZOP -Zero Order Prediction and SAPA - Scan Along Polygonal Approximation), and beat detection method (Peak) both or which need small numbers of operations to perform electrogram compression. Compression ratio (CR) and percent root mean square difference (PRD) were used to compare the three methods, with statistical analyses performed using paired t-test. Results and Conclusion. The best performance was obtained using the Peak method which reaches an average CR of 10.6 in the case of SR group, 2.8 for AF, and 3.6 for AFL groups, respectively, while PRD lies below 2% for SR and AFL groups and 6% for the AF group. Results show that, for bipolar electrograms, the Peak method reaches statistically significant better performance (P<0.001) in all cases except for Peak vs SAPA applied to AF (P=0.2). The number of operations necessary to compress the data indicate that time consumption can be reduced to be suitable for real time compression in implantable devices. The Peak method, which was assumed to receive the instant of occurrence of each recognized beat, from the hardware of the device, requires fewer operations than ZOP and SAPA. Increasing the length of electrograms recorded in pacemakers will enhance the amount of information provided by the implantable device, allowing more detailed characterization of the intra-cardiac activity and leading to new perspectives in arrhythmia diagnosis and therapy. © 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved

Low complexity methods for intracardiac atrial electrogram compression

Methods for intracardiac atrial electrograms compression suitable with implementation on implantable devices were studied. Bipolar intracardiac electrograms were obtained during electrophysiological studies and divided in three rhythm groups. 2196 seconds of sinus rhythm (SR), 786 sec. of atrial fibrillation (AF) and 1793 sec. of atrial flutter (AFL) were analyzed. Preliminary results show that time consuming can be reduced to suitability with real time compression on implantable devices

Linear and Non-Linear Indices of Heart Rate Variability in Chronic Heart Failure: Mutual Interrelationships and Prognostic Value

We computed 3 linear and 20 nonlinear HRV indexes on 24-h Holter recordings from 200 stable CHF patients (age 52 +/- 9 yrs, NYHA II-III, LVEF 24 +/- 6%) with the aim to assess i) the mutual interrelationships between these indexes and ii) their prognostic value towards cardiac death. We found high correlations between variables, with potential bias in fitting survival models. To overcome this problem a clustering procedure was used, obtaining 11 clusters. Cox analysis showed that seven clusters were significantly associated with the study outcome (p < 0.05) but, after adjustment for major clinical prognostic parameters, significance persisted only in 2 of them (both composed by nonlinear variables). Our results indicate that composite scores derived from nonlinear indices contain significant prognostic information independent of classical clinical predictors, highlighting the importance of non linear HRV parameters in prognostic stratification of CHF patients