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Forleo G.B.,University of Rome Tor Vergata | Di Biase L.,The Texas Institute | Di Biase L.,University of Foggia | Di Biase L.,Yeshiva University | And 11 more authors.
Journal of Interventional Cardiac Electrophysiology | Year: 2013

Purpose: A new four-pole connector system (DF-4) for transvenous high-voltage implantable cardioverter defibrillators (ICD) is currently available in clinical practice. However, no clinical data demonstrating the safety and effectiveness of this complex electromechanical design is available. This study aims to test the safety and effectiveness of this newly designed system compared to the conventional DF-1 leads. Methods: During a 3-year period, 351 consecutive patients were implanted with DF-4 leads as part of an ICD or ICD-cardiac resynchronization therapy system. Patients were matched for age, sex, and follow-up with 154 patients implanted with a standard DF-1 lead. The primary outcome of the study was defibrillation lead failure, defined as the need for lead removal or capping. Operative, electrical, and safety data were obtained at implant and during postoperative follow-up. Results: Implantation success rate in both groups was 100 %. A trend towards shorter procedure time was observed in the DF-4 group but the difference did not reach statistical significance. Handling characteristics of the DF-4 leads were graded better than those of DF-1 models. During a total follow-up of 8,130.5 lead-months, there were nine ICD-lead failures (four system erosion/infections and five electrical lead dysfunctions). The overall incidence of electrical lead failure was 0.64 vs. 0.97 per 100 lead-years, for DF-4 and DF-1 leads, respectively (P = 0.2). Conclusions: This multi-center experience provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional DF-1 leads. © 2013 Springer Science+Business Media New York.

Proietti R.,Electrophysiology Laboratory | Manzoni G.,Psychology Research Laboratory | Manzoni G.,University of Milan | Di Biase L.,The Texas Institute | And 16 more authors.
PACE - Pacing and Clinical Electrophysiology | Year: 2012

Introduction: Closed-loop stimulation (CLS) is a form of rate-adaptive pacing capable of providing an effective pacing rate profile not only during physical exercise but also during mental stress. To test its effectiveness, CLS and accelerometer sensor (AS) rate response were compared intraindividually during a mental stress test (MST). Methods: Thirty-six patients (mean age 78.9 ± 6.4 years) implanted with a pacemaker with the CLS algorithm (Cylos, Biotronik, Berlin, Germany) underwent MSTs in different pacing configurations: nonrate-adaptive mode (VVI), AS mode (VVIR), and CLS mode, respectively. A modified Stroop test was used in order to induce mental stress. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure, and pacing percentage burden were collected for 5 minutes before, during, and 5 minutes after the test. Results: Mean peak-HR during MST was significantly higher in CLS configuration than in VVIR and VVI modes (92.8 ± 12.6 vs 78.9 ± 6.5 vs 77.8 ± 7.5; P ≤ 0.001). The average HR increase during MST was also higher in CLS configuration than in VVIR and VVI modes (22.7 ± 16.7 vs 8.2 ± 8.6 vs 6.6 ± 6.3; P ≤ 0.001). The percentage of pacing beats during MST was higher in CLS configuration than with the other two algorithms (48.4 ± 17.9 vs 27.4 ± 17.5 vs 25.8 ± 17.6; P ≤ 0.001). The average peak-SBP was significantly higher during MST in CLS mode than in VVIR and VVI configurations (172.6 ± 15.5 vs 156.7 ± 12.2 vs 145.5 ± 13.7; P ≤ 0.001). The mean SBP increase showed a similar behavior (51.8 ± 24.7 vs 18.4 ± 13.7 vs 16.4 ± 10.3; P ≤ 0.001). Conclusion: CLS algorithm in a single-chamber device is more effective than AS in detecting an hemodynamic demand due to an emotional stress and supplying a proper HR increase. These results are even more surprising compared to previous data in dual-chamber pacemakers, because they imply that CLS algorithm can provide an appropriate rate-modulation in patients with AF and chronotropic incompetence. (PACE 2012; 35:990-998) © 2012 Wiley Periodicals, Inc.

Gerritsma M.,Technical University of Delft | Hiemstra R.,University of Austin | Kreeft J.,Royal Dutch Shell | Palha A.,Technical University of Delft | And 2 more authors.
Lecture Notes in Computational Science and Engineering | Year: 2014

The relation between physics, its description in terms of partial differential equations and geometry is explored in this paper. Geometry determines the correct weak formulation in finite element methods and also dictates which basis functions should be employed to obtain discrete well-posedness. © Springer International Publishing Switzerland 2014.

Kwon O.-S.,University of Toronto | Kim E.,University of Austin | Orton S.,University of Missouri
Journal of Bridge Engineering | Year: 2011

In this paper, the live load factor in the Strength I Limit State in the AASHTO LRFD Bridge Design Specifications is calibrated based on state-specific traffic environments and bridge configurations. As the initial development of the live load factor in the LRFD specifications was intended to be applied at the national level, state-specific traffic conditions, such as traffic volume, truck load, or bridge configurations, were not considered in the development process. In addition, due to the lack of reliable U.S. truck weight data in the early 1990s, truck data from Ontario, Canada, collected in the 1970s were used for the initial AASHTO calibration. Hence, the application of the live load factor in the LRFD specifications may result in over- or under-designed bridges for a specific state. Through reliability analysis of bridges based on state-specific traffic and bridge conditions, the live load factor can be recalibrated to achieve both reliable and economical bridge design. In this study, the traffic data collected for 5 years at weigh-in-motion stations in Missouri are used to simulate realistic truck loads. In addition, typical bridge configurations identified from statistical analyses of 2007 National Bridge Inventory are used to define representative bridges in Missouri. Reliability analysis results using the weigh-in-motion data and the representative bridge configurations show that most bridges have reliability indexes higher than 3.5. Live load calibration factors for the design of new bridges in Missouri are proposed as a function of the bridge's average daily truck traffic. © 2011 American Society of Civil Engineers.

Proietti R.,Cardiac Electrophysiology Laboratory | Proietti R.,McGill University | Pecoraro V.,IRCCS Orthopedic Institute Galeazzi | Di Biase L.,The Texas Institute | And 12 more authors.
Europace | Year: 2013

The aim of this study was to determine the efficacy and safety of remote magnetic navigation (RMN) with open-irrigated catheter vs. manual catheter navigation (MCN) in performing atrial fibrillation (AF) ablation. We searched in PubMed (1948-2013) and EMBASE (1974-2013) studies comparing RMN with MCN. Outcomes considered were AF recurrence (primary outcome), pulmonary vein isolation (PVI), procedural complications, and data on procedure's performance. Odds ratios (OR) and mean difference (MD) were extracted and pooled using a random-effect model. Confidence in the estimates of the obtained effects (quality of evidence) was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. We identified seven controlled trials, six non-randomized and one randomized, including a total of 941 patients. Studies were at high risk of bias. No difference was observed between RMN and MCN on AF recurrence [OR 1.18, 95% confidence interval (CI) 0.85 to 1.65, P = 0.32] or PVI (OR 0.41, 95% CI 0.11-1.47, P = 0.17). Remote magnetic navigation was associated with less peri-procedural complications (Peto OR 0.41, 95% CI 0.19-0.88, P = 0.02). Mean fluoroscopy time was reduced in RMN group (-22.22 min; 95% CI-42.48 to-1.96, P = 0.03), although the overall duration of the procedure was longer (60.91 min; 95% CI 31.17 to 90.65, P < 0.0001). In conclusion, RMN is not superior to MCN in achieving freedom from recurrent AF at mid-term follow-up or PVI. The procedure implies less peri-procedural complications, requires a shorter fluoroscopy time but a longer total procedural time. For the low quality of the available evidence, a proper designed randomized controlled trial could turn the direction and the effect of the dimensions explored. © 2013 The Author.

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