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This work develops a mathematical model for the atrioventricular (AV) node in the human heart, based on recordings of electrical activity in the atria (the upper chambers of the heart) and the ventricles (the lower chambers of the heart). Intracardiac recordings of the atrial and ventricular activities were recorded from one patient with atrial flutter and one with atrial fibrillation. During these arrhythmias, not all beats in the atria are conducted to the ventricles. Some are blocked (concealed). However, the blocked beats can affect the properties of the AV node. The activation times of the atrial events were regarded as inputs to a mathematical model of conduction in the AV node, including a representation of AV nodal concealment. The model output was compared to the recorded ventricular response to search for and identify the best possible parameter combinations of the model. Good agreement between the distribution of interbeat intervals in the model and data for durations of 5 min was achieved. A model of AV nodal behavior during atrial flutter and atrial fibrillation could potentially help to understand the relative roles of atrial input activity and intrinsic AV nodal properties in determining the ventricular response.

This study examined the effects of being victimized by peers on children's behavioral, social, emotional, and academic functioning. We assessed an ethnically diverse sample of 2,064 first, second, and fourth graders and followed them over 2 years, locating 1,469 of the participants at the follow-up. Correlation and partial correlation analyses revealed that prior victimization predicted externalizing, internalizing, and social problems 2 years later for the sample as a whole. However, not all victimized children experienced the same types of outcomes; instead, there was heterogeneity in children's responses to victimization. Using cluster analysis, we identified eight outcome patterns that represented different patterns of functioning. These were labeled as externalizing, internalizing, symptomatic, popular, disliked, absent, low achieving, and high achieving. Discriminant function analyses revealed that the symptomatic, externalizing, and disliked patterns were systematically related to victimization. Moreover, significant gender and age differences in the severity of effects were obtained. The discussion highlights the complexity of victimization effects.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, the prevalence of which is increasing with the aging of the population. Because of its clinical importance and the lack of highly satisfactory management approaches, AF is the subject of active clinical and research efforts. This paper reviews recent and on-going developments in pharmacological and non-drug management of AF. The ideal therapeutic goal for AF is the production and maintenance of sinus rhythm. Comparative studies suggest that available class I and III drugs have comparable and modest efficacy for sinus rhythm maintenance. Amiodarone, with actions of all antiarrhythmic classes, has recently been shown to have clearly superior efficacy compared with other available drugs. Newer agents are in development, but their advantages are as yet unclear and appear limited. A potentially interesting approach is the prescription of drugs upon the occurrence of an attack, rather than on a continuous basis. Recent insights into AF mechanisms may permit therapy to prevent development of the AF substrate. An alternative to sinus rhythm maintenance is a rate control approach, with no attempt to prevent AF. Drugs to effect rate control include digitalis, β-blockers and calcium channel antagonists. Digitalis has limited value for control of exercise heart rate and for paroxysmal AF, but is particularly well suited for patients with concomitant AF and congestive heart failure. AV-nodal ablation and pacing is an effective alternative for rate control but leaves the patient pacemaker dependent. The relative merits of rate versus rhythm control are being evaluated in ongoing trials, preliminary results of which indicate no statistically significant differences in primary endpoints but highlight the risks of rhythm control therapy. In patients requiring pacemakers, physiological pacing (dual chamber devices or atrial pacing) has an advantage over purely ventricular pacemakers in AF prevention. Newer pacing modalities that produce more synchronised atrial activation, as well as pacemakers that prevent excessive atrial rate swings, show promise in AF prevention and may soon see wider use. The usefulness of automatic atrial defibrillators is presently limited by discomfort during shocks. Targeted destruction of pulmonary vein foci by radiofrequency catheter ablation suppresses paroxysmal AF. Efficacy in persistent AF is lower and still under study. Problems include potential recurrence in other veins and a small but non-trivial risk of pulmonary vein stenosis. Surgical division of the atria into zones with limited electrical connection, the MAZE procedure, is highly effective in AF prevention but is a major intervention that is not applicable to most patients. In conclusion, significant advances are being made in the management of patients with AF but much more work remains to be done.

Este artículo se enmarca en el estudio de los estándares de la televisión digital en todo el mundo, en comparativa con el estándar empleado adoptado en Ecuador es el japonés con modificaciones hechas en Brasil (ISDB-Tb). Se abordan temas técnicos como la transmisión jerárquica y los modos de difusión para garantizar una cobertura de buena calidad hacia el televidente. Este estándar cuenta con un middleware llamado Ginga, el cual permite implementar nuevos servicios orientados a muchos sectores sociales públicos o privados. El estudio del middleware incorporado (Ginga), permite diseñar, configurar y generar flujos de transporte con contenido audio visual; este middleware podría ser útil para brindar nuevos servicios públicos o privados en la televisión digital.

Hypertension is an established risk factor for new-onset atrial fibrillation (AF). However, the relationship between blood pressure and recurrent AF is less well understood.A pooled analysis of patient-level data from AFFIRM and AF-CHF trials was conducted on all 2,715 patients with paroxysmal or persistent AF, 68 ± 8 years, 66% male, randomized to rhythm control and followed for 40.6 ± 16.5 months. We assessed the impact of a baseline systolic blood pressure (SBP;120 mmHg [N = 1,008], 120-140 mmHg [N = 930],140 mmHg [N = 777]) on recurrent AF and proportion of time spent in AF. In patients with LVEF40% (N = 1,719), SBP was not associated with recurrent AF in multivariate regression analyses (P = 0.752). In contrast, in patients with LVEF ≤40% (N = 996), the AF recurrence rate was higher in those with an SBP140 mmHg compared to 120-140 mmHg (hazard ratio 1.47; 95% CI [1.12-1.93], P = 0.005). The rate of recurrent AF was similar in patients with SBP120 mmHg compared to 120-140 mmHg (hazard ratio 1.15; 95% CI [0.92-1.43], P = 0.225). Consistently, the proportion of time spent in AF was not influenced by SBP in patients with LVEF40% (P = 0.645). However, in patients with LVEF ≤40%, the adjusted mean proportion of time spent in AF was 17.2% if SBP was120 mmHg, 15.4% for SBP 120-140 mmHg, and 24.0% for SBP140 mmHg (P = 0.025).Systolic blood pressure is an important determinant of recurrent AF and overall AF burden in patients with left ventricular dysfunction (LVEF≤40%) but not in those with preserved ventricular function.

Background— Phrenic nerve palsy remains the most frequent complication associated with cryoballoon-based pulmonary vein (PV) isolation. We sought to characterize our experience using a novel monitoring technique for the prevention of phrenic nerve palsy. Methods and Results— Two hundred consecutive cryoballoon-based PV isolation procedures between October 2010 and October 2013 were studied. In addition to standard abdominal palpation during right phrenic nerve pacing from the superior vena cava, all patients underwent diaphragmatic electromyographic monitoring using surface electrodes. Cryoablation was terminated on any perceived reduction in diaphragmatic motion or a 30% decrease in the compound motor action potential (CMAP). During right-sided ablation, a ≥30% reduction in CMAP amplitude occurred in 49 patients (24.5%). Diaphragmatic motion decreased in 30 of 49 patients and was preceded by a 30% reduction in CMAP amplitude in all. In 82% of cases, this reduction in CMAP amplitude occurred during right superior PV isolation. The baseline CMAP amplitude was 946.5±609.2 mV and decreased by 13.8±13.8% at the end of application. This decrease was more marked in the 33 PVs with a reduction in diaphragmatic motion than in those without (40.9±15.3% versus 11.3±10.5%; P Conclusions— Electromyographic phrenic nerve monitoring using the surface CMAP is reliable, easy to perform, and offers an early warning to impending phrenic nerve injury.

Background Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is associated with PV to left atrium reconduction. Effective lesion creation necessitates adequate contact force between the ablation catheter and myocardium. Objective The purpose of this study was to study the utility of contact force–guided ablation on immediate and long-term outcomes. Methods Seventy-five patients with highly symptomatic paroxysmal AF underwent wide circumferential PVI using an irrigated-tip radiofrequency catheter. In 25 patients, ablation was guided by real-time contact force measurements (CF group; SmartTouch, Biosense Webster). A control group of 50 patients underwent PVI using a standard nonforce sensing catheter (standard group; ThermoCool, Biosense Webster). After PVI, all patients underwent adenosine testing to unmask dormant conduction. Patients were followed up at 3, 6, and 12 months and by transtelephonic monitoring as well. Results Dormant conduction was unmasked and subsequently eliminated in 4 PV pairs (8%; 16% of patients) in the CF group and 35 PV pairs (35%; 52% of patients) in the standard group ( P = .0004 per PV pair; P = .0029 per patient). The single-procedure, off–antiarrhythmic drug freedom from recurrent atrial arrhythmias at 1 year was 88% in the CF group vs 66% in the standard group ( P = .047). Procedure duration and fluoroscopy time were significantly longer in the CF group ( P = .0038 and P = .0001, respectively). Conclusion The use of real-time contact force guidance results in a significant reduction in the prevalence of dormant conduction with improved long-term freedom from recurrent arrhythmias. The utility of a contact force–guided approach requires evaluation in a long-term prospective randomized study.

Cardiac resynchronization therapy (CRT) implant procedures are often complex and prolonged, resulting in significant ionizing radiation (IR) exposure to the patient and operator. We report our early experience working with a novel sensor-based electromagnetic tracking system (MediGuide™, MDG, St. Jude Medical Inc., St. Paul, MN, USA), in terms of procedural IR exposure reduction.Information regarding patient demographics, procedural details, procedural duration, and IR exposure were prospectively collected on 130 consecutive CRT procedures performed between January 2013 and January 2014. Sixty procedures were performed with MDG guidance, and 70 were performed without MDG guidance. Despite a nonsignificant trend toward shorter procedure duration with the use of MDG (120 minutes vs 138 minutes with non-MDG, P = 0.088), a 66% reduction in total IR exposure (median 769 μGray · m(2) vs 2,608 μGray · m(2), P0.001) was found. This reduction was primarily driven by a90% reduction in IR dose required to cannulate the coronary sinus (median 80 μGray · m(2) vs 922 μGray · m(2), P0.001), and to a lesser extent from a reduction in IR dose required for LV lead placement (median 330 μGray·m(2) vs 737 μGray · m(2), P = 0.059). In addition, a significant learning curve effect was observed with a significantly shorter procedural duration for the last 15 cases compared to the first 15 cases (median 98 minutes vs 175 minutes, P0.001).The nonfluoroscopic MDG positioning system is associated with a dramatic reduction in exposure to IR during CRT implant procedures, with a 90% decrease in the IR dose required to cannulate the coronary sinus. A steep learning curve was quantified.

Despite amiodarone's established safety profile in the setting of heart failure, it is unknown whether its impact on cardiovascular outcomes in patients with atrial fibrillation is modulated by left ventricular function.A pooled analysis of 3,307 patients (age 68.0 ± 0.2 years; 31.1% female) enrolled in AFFIRM and AF-CHF trials was conducted to assess the effect of rhythm control with amiodarone on cardiovascular outcomes, according to left ventricular systolic function. In amiodarone-treated patients (N = 1,107), freedom from recurrent atrial fibrillation was 84% and 45% at 1 and 5 years, respectively, with no differences according to left ventricular function (P = 0.8754). Similarly, the adjusted proportion of time spent in atrial fibrillation (15.0 ± 1.8%) did not vary according to ventricular function (P = 0.6094). Over 40.0 ± 0.3 months of follow-up, 1,963 (59.4%) patients required at least one hospitalization, 1,401 (42.6%) of whom had cardiovascular-related hospitalizations. Adjusted all-cause and cardiovascular hospitalization rates were similar with amiodarone versus rate control in all patients and in subgroups with and without severe left ventricular dysfunction. A total of 729 (22.0%) patients died, 498 (15.1%) from cardiovascular causes. Adjusted all-cause and cardiovascular mortality rates were similar with amiodarone versus rate control overall and in subgroups with and without severe left ventricular dysfunction.Amiodarone's efficacy in maintaining sinus rhythm and reducing the burden of atrial fibrillation is similar in the presence or absence of severe left ventricular dysfunction. Rhythm control with amiodarone is associated with comparable hospitalization and mortality rates to rate control in patients with and without left ventricular dysfunction.

Atrial fibrillation (AF) is the most common sustained arrhythmia seen in clinical practice, affecting approximately 1% of the overall population. While rarely life-threatening, AF is almost universally associated with increased morbidity and mortality, predominantly through an increased risk of thromboembolic events, left ventricular dysfunction, as well as significant impairments in functional capacity and health-related quality of life (HRQOL).[1-8] Improvement in HRQOL, with a secondary reduction of disability and health-care resource utilization, is one of the major therapeutic goals in the management of AF.

Background Patients with Brugada syndrome (BrS) are at risk for ventricular arrhythmias (VAs) and sudden death. Identification of high-risk individuals beyond those with syncope or resuscitated sudden death remains a major challenge. Methods We assessed the value of clinical, electrophysiological, and electrocardiographic (ECG) features, including depolarization and repolarization metrics, in predicting arrhythmic events and sudden death in consecutive patients with BrS diagnosed between 2002 and 2013 in Quebec, Canada. Qualifying electrocardiograms with the highest type 1 ST-segment elevations were reviewed and analyzed by 2 electrophysiologists who were blinded to clinical history. Survival analyses were adjusted for Firth bias correction and left truncation. Results A total of 105 patients, 79.8% of whom were men, were diagnosed with BrS at a mean age of 46.2 ± 13.3 years and were followed for 59.6 ± 16.4 months. Ten (9.5%) had a history of cardiac arrest, 37 (35.2%) had syncope, and 7 (6.7%) experienced 20 arrhythmic events during follow-up, all consisting of appropriate ICD therapy (7 antitachycardia pacing; 13 shocks). In multivariate Cox regression analyses, a spontaneous type 1 electrocardiographic (ECG) pattern (hazard ratio [HR], 10.80; 95% confidence interval [CI], 1.03-113.87; P = 0.0476), maximal T peak-end (T p-e ) duration ≥ 100 ms (HR, 29.73; 95% CI, 1.33-666.37; P = 0.0325), and QRS duration in lead V 6 > 110 ms (HR, 15.27; 95% CI, 1.07-217.42; P = 0.0443) were independently associated with VAs or aborted sudden cardiac death. Conclusions In a multicentre cohort with BrS from Quebec, Canada, VAs and sudden death were independently associated with standard 12-lead ECG features, including a spontaneous type 1 pattern, depolarization (QRS in lead V 6 ), and repolarization (maximal T p-e duration) criteria.

Background Invasively measured maximum increase in left ventricular pressure (LV dP/dtmax) has been used to assess biventricular (BiV) pacing. We quantified extracardiac factors contributing to its variability, and developed a protocol to minimize these effects in an acute pacing experiment. Methods and Results Continuous pressure was recorded by a guidewire sensor placed in the LV. Four to six test pacing interventions were performed, each repeated 3 times and followed by a baseline pacing configuration. Maximum increase in LV dP/dtmax from any measurement of BiV pacing was median 20.3% in 25 patients, compared with BiV pacing off. When directly comparing sequential measurements with BiV pacing on and off, median increase was 7.4%. Noncardiac sources of modulation included respiratory variation (6.4%), drift from first to last baseline measurement (5.0%), and discrepancy among repeated recordings of the same pacing intervention (3.3%). Comparing test interventions to interleaved baseline measurements reduced discrepancy among recordings to 2.1%; P Conclusions With repeated measurements of baseline state, and by comparing test interventions only to baseline measurements performed before and after, it is possible to minimize extracardiac factors and focus on the effects of test pacing interventions.

Background— Atrial fibrillation recurrence after pulmonary vein (PV) isolation is associated with PV to left atrium reconduction. We prospectively studied the use of 2 procedural techniques designed to facilitate identification of residual gaps within the index ablation line. Methods and Results— After wide circumferential PV isolation, 40 patients received additional ablation targeted at locations of left atrial capture during high-output pacing (pace-capture group), while 40 patients underwent adenosine testing with targeted ablation at sites of dormant conduction (adenosine group). Patients were followed up at 3, 6, and 12 months. After PV isolation, high-output pace-capture was documented in 39 PVs (25%; 50% of patients) in the pace-capture group. Dormant conduction was unmasked in 34 PVs (22%; 53% of patients) in the adenosine group. A subset of 25 patients in the pace-capture group underwent adenosine testing without targeted ablation of dormant conduction. In these patients, only 10 out of 86 PVs (11.6%; 24% of patients) demonstrated dormant conduction after the elimination of local pace-capture. At a follow-up of 329±124 days, the single procedure off antiarrhythmic drug freedom from recurrent atrial fibrillation was 67.5% in the adenosine group and 65.0% in the pace-capture group ( P =0.814). Procedure duration and fluoroscopy time were significantly longer in the pace-capture group ( P =0.002 and P P =0.192). Conclusions— The use of high-output pacing post-PV isolation results in a significant reduction in the incidence of dormant conduction with a comparable long-term freedom from recurrent atrial fibrillation (versus adenosine-guided ablation). The use of these approaches requires evaluation in a long-term prospective randomized study.

Competitiveness of Brachiaria decumbens cv. Basilisk and Stylosanthes guianensis cv. Minerao was investigated either without root restriction or by separating their root systems with a fine mesh or a solid barrier in the presence or absence of mycorrhiza (Glomus clarum). Nitrogen transfer between the legume and the grass was assessed with the 15N isotope dilution technique using a relatively stable 15N-enriched soil derived from a long-term labelling experiment. During establishment, legume development was severely restricted by competition from the grass in pots without a root barrier. However, as the system became N limited, the legume became dominant due to its access to atmospheric N2 which contributed over 80% of the legume N requirements. S. guianensis was highly mycotrophic and inoculation with mycorrhiza favoured rapid establishment even in the treatments with no root barrier. Only in the presence of root barriers, either a mesh or a complete compartment separation, was the proportion of N derived from N2 fixation positively affected by the presence of the fungus. No significant direct belowground N transfer from legume to grass was observed during the lifetime of the legume suggesting that the legume maintains a highly efficient recycling under N-limited conditions. However, after cutting the shoot at ground level, the grass assimilated significant amounts of N derived from decaying legume roots. We conclude that the main pathway of belowground N transfer from S. guianensis to associated B. decumbens occurred via decomposing roots rather than via root exudates or direct mycorrhizal hyphae transfer.

Background —We report the first successful slow pathway ablation using a novel catheter-based cryothermal technology for the elimination of atrioventricular nodal reentrant tachycardia (AVNRT). Methods and Results —Eighteen patients with typical AVNRT underwent cryoablation. Reversible loss of slow pathway (SP) conduction during cryothermy (ice mapping) was demonstrated in 11 of 12 patients. Because of time constraints, only 2 sites were ice mapped in 1 patient. Seventeen of 18 patients had successful cryoablation of the SP. One patient had successful ice mapping of the SP, but inability to cool beyond −38°C prevented successful cryoablation. A single radiofrequency lesion at this site eliminated SP conduction. No patient has had recurrent AVNRT over 4.9±1.7 months of follow-up. During cryoablation, accelerated junctional tachycardia was not seen and was therefore not available to guide lesion delivery. Adherence of the catheter tip during cryothermy (cryoadherence) allowed atrial pacing to test for SP conduction. Cryoablation in the anterior septum produced inadvertent transient PR prolongation consistent with loss of fast pathway conduction in 1 patient and transient (6.5 seconds) 2:1 AV block in another. On rewarming, the PR interval returned to normal, and the AV nodal effective refractory period was unchanged in both. Accelerated junctional tachycardia was seen on rewarming in both but not during cryothermy. Conclusions —Cryothermal ablation of the SP was achieved in patients with this novel technique. Successful ice mapping of both the SP and fast pathway was demonstrated. The ability to test the functionality of specific ablation sites before production of a permanent lesion may eliminate inadvertent AV block.

This study examined aggression and withdrawal as predictors of peer victimization. In addition, peer rejection was evaluated as both a moderator and mediator of these relations. The sample consisted of 1956 African-American, Hispanic, and White elementary school-aged boys and girls attending urban and inner-city schools that were classified as high or moderate disadvantage. Correlation and regression analyses revealed that aggression predicted both contemporaneous and longitudinal victimization by peers. This relation maintained across school disadvantage, ethnicity, age, and sex, andwas mediated by rejection. Withdrawal, mediated by rejection, predicted victimization for fourth graders only; withdrawal also reduced risk for victimization for low rejected children. The implications for understanding the dynamics of childhood victimization and intervention are discussed.

This study examines the prevalence, stability, and contextual correlates of peer victimization in a sample of African-American, Hispanic, and non-Hispanic White urban elementary school-age children. A total of 1956 children (40% African-American, 42% Hispanic, and 18% White) attending any 1 of 14 public elementary schools located in one large and one mid-sized Midwestern city participated in this study. Peer ratings of victimization were obtained at two points in time, separated by a 2-year period. Findings revealed that risk for being victimized by peers varied by ethnicity and by school context. Hispanic children had lower victimization scores than did either African-American or White children. These findings, however, were moderated by school context, such that attending ethnically integrated schools was associated with a significantly higher risk of victimization for White children and a slightly lower risk of victimization for African-American children and did not affect the risk of victimization for Hispanic children. In addition, African-American children were less likely than Hispanic and White children to be repeatedly victimized by peers over time. The importance of considering ethnicity and context in explaining peer victimization is discussed and suggestions for preventive interventions and future research are provided.

Viewpoints: A Guide to Conflict Resolution and Decision Making for Adolescents is about understanding yourself, others and their points of view; confronting common problems; and solving them effectively. Problems within one's control can be solved and the manual can be of assistance in this process if used on one's own or in small groups. Lessons include: Thinking About Our Problems, Is There a Problem? Why Is There a Conflict? and What Do I Want?

Biomembranes are frequently proposed as devices for “guided bone regeneration.” Such membranes consist generally of a thin sheet of polymeric material, mostly textured from polymeric yarns or clots, which all have a diffuse very fine winding porosity. The cross-section size of the holes of such porosity is nanometric (diameter < 0.1 μm); thus these holes can be indicated as nanoholes. Whatever the method of production, the surface density of nanoholes (number per square centimeter) has to be as high as possible. It is important also that no variation of this density occurs. The fine dimension of these microholes allows the crossing of small molecules (O2, CO2, H2O, sugars, many nutritional organic compounds and even some simple proteins) but not other larger molecules and particulates, including cells of any kind. These biomembranes have, consequently, a semipermeable behavior, providing the functional role which is the interposition of a barrier for the cells, separating the bone from the surrounding soft tissues. The kinetic of proliferation of osteoblasts is lower than that of fibroblasts. Most membranes of this kind are not resorbable. The main problem for the resorbable ones is the speed of size increase of the holes during the time. Their diameter must not exceed a threshold value until the reconstruction of bone is complete, otherwise soft tissue cells will invade the growing bone tissue with formation of undesirable mixed tissue. The present paper deals with a resorbable membrane made with a composite polymer/ceramic. A poly(ɛ-caprolactone)-block-poly(oxyethylene)-block-poly(ɛ-caprolactone) copolymer is the polymeric matrix which contains dispersed ceramic hydroxyapatite microgranules, a stiff filling additive. The main possible use is that of periodontal membranes. The copolymer, obtained by thermal polymerization of ɛ-caprolactone onto poly(ethylene-glycol), presents good biological tolerance, is resorbable under physiological conditions and can promote cell growth. Histological tests, performed 6 months after implantation, showed that the polymeric matrix is almost totally resorbed. New-formed bone colonizes even the innermost parts of the membrane, with bone trabeculae closely surrounding the hydroxyapatite granules. © 1999 Kluwer Academic Publishers

We consider a linear identification problem related to a first order integrodifferential equation in a Banach space. For such a problem we prove some existence, uniqueness and continuous dependence results in the large. Then we apply such results to the identification of a family of relaxation kernels in linear first-order symmetric systems related to either ${\mathbb{R}}^n$ or any (smooth) domain in ${\mathbb{R}}^n$. Particular attention is paid to the case of Maxwell systems

Osteochondroma is one of the most common benign tumors of the axial skeleton. Location of a solitary exostosis in the scapula is relatively rare. We report the case of an osteochondroma of the scapula in a 13-year-old boy. Because of the atypical location with nonspecific shoulder pain, the diagnosis is often made late. CT is necessary to determine the correct position of the osteochondroma. Despite the young age of the patient, surgical excision of the exostosis was performed, because of an arising thoracic pressure pain. The outcome was good, the patient noticed disappearance of previous painful symptoms, and a normal profile of the scapula was gained.

s S333 537 LONG-TERM SURVIVAL AFTER IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IMPLANTATION: A POPULATION-BASED STUDY M Bennett, D Ayers, L Ding, H Jackson, A Krahn Vancouver, British Columbia BACKGROUND: In the era of potential differences in Implantable Cardioverter Defibrillator (ICD) complexity and longevity, an estimation of patient lifespanmay allow for patient specific device selection that influence both clinical utility and cost-effectiveness of the device.We sought to evaluate patient survival from British Columbia’s Implantable Arrhythmia Device Registry. METHODS: All BC patients aged 20 or older, who underwent ICD implants or generator replacement from 01 January 2000 to 31 December 2012, were included in this study. Patient demographic, clinical, procedural, device-related data were obtained from the BC Cardiac Services Registry. Mortality data were obtained from the Vital StatisticsAgency.Theprobabilities of survivalwere estimatedby the Kaplan-Meier method with all-cause mortality as the end-point. RESULTS: 5241 patients (4282 male, 81.7%; 959 female, 18.3%) underwent 6929 ICD implantations (4369 initial implants; 2560 generator changes) with a total of 268,001 patientyears of follow-up. Five and 10year survival rateswere 76.6%and 60.9% respectively. The median patient age was 66 years (IQR: 57, 73). Patients were divided into 10 year age groups. The percentage of patients surviving greater than 5 years from last procedure in the 41-50, 51-60, 61-70, 71-80, and 81-90 year age groupswas 91.0, 86.2, 78.7, 63.0, and49.0, respectively.The percentage of patients surviving greater than 10 years in the 4150, 51-60, 61-70, 71-80, and 81-90 year age groups was 81.6, 73.5, 58.4, 39.0, and 28.1, respectively. Overall, women had a significantly longer survival thanmen (5 year survival rate 82.9 vs. 75.1%), as a consequence of amarkedly lower age at implantation (median 62 years vs. 66 years, P

BACKGROUND: It has been well described that women who undergo ICD implantation receive less appropriate ICD therapy than men, but suffer a similar mortality. The benefit of ICD implantation in women has been questioned. We sought to investigate this observation further to better understand how sex affects the occurrence of ventricular arrhythmia in an ICD population. METHODS: All patients who were included in a registry of patients receiving ICDs in Nova Scotia were assessed for inclusion into the study. Patients who received ICDs for inherited cardiomyopathies and ion channelopathies were excluded from the study. Data collection was performed in the form of a retrospective chart review from 20042006, but then was carried on prospectively from 20062013. Follow-up for the patients in the registry conformed to current guidelines for patients with ICDs. All arrhythmic events including ATP and ICD shocks were adjudicated by two electrophysiologists. Baseline characteristics were collected through chart review. Procedural complications were collected through chart review. Mortality was collected through linkage with Vital Statistics in Nova Scotia. RESULTS: A total of 776 patients were included in the study; 135 (17.4%) of these were women. Overall, women had a lower risk of ischemic heart disease (49.6% vs 76.8%, p

Normative beliefs have been defined as self-regulating beliefs about the appropriateness of social behaviors. In 2 studies the authors revised their scale for assessing normative beliefs about aggression, found that it is reliable and valid for use with elementary school children, and investigated the longitudinal relation between normative beliefs about aggression and aggressive behavior in a large sample of elementary school children living in poor urban neighborhoods. Using data obtained in 2 waves of observations 1 year apart, the authors found that children tended to approve more of aggression as they grew older and that this increase appeared to be correlated with increases in aggressive behavior. More important, although individual differences in aggressive behavior predicted subsequent differences in normative beliefs in younger children, individual differences in aggressive behavior were predicted by preceding differences in normative beliefs in older children.

Bullying involvement in any form can have lasting physical and emotional consequences for adolescents. For programs and policies to best safeguard youth, it is important to understand prevalence of bullying across cyber and traditional contexts. We conducted a thorough review of the literature and identified 80 studies that reported corresponding prevalence rates for cyber and traditional bullying and/or aggression in adolescents. Weighted mean effect sizes were calculated, and measurement features were entered as moderators to explain variation in prevalence rates and in traditional-cyber correlations within the sample of studies. Prevalence rates for cyber bullying were lower than for traditional bullying, and cyber and traditional bullying were highly correlated. A number of measurement features moderated variability in bullying prevalence; whereas a focus on traditional relational aggression increased correlations between cyber and traditional aggressions. In our meta-analytic review, traditional bullying was twice as common as cyber bullying. Cyber and traditional bullying were also highly correlated, suggesting that polyaggression involvement should be a primary target for interventions and policy. Results of moderation analyses highlight the need for greater consensus in measurement approaches for both cyber and traditional bullying.

Hemi-diaphragmatic paralysis is the most common complication associated with cryoballoon ablation for atrial fibrillation, yet the histopathology of phrenic nerve injury has not been well described.A preclinical randomized study was conducted to characterize the histopathology of phrenic nerve injury induced by cryoballoon ablation and assess the potential for electromyographic (EMG) monitoring to limit phrenic nerve damage. Thirty-two dogs underwent cryoballoon ablation of the right superior pulmonary vein with the objective of inducing phrenic nerve injury. Animals were randomized 1:1 to standard monitoring (i.e., interruption of ablation upon reduction in diaphragmatic motion) versus EMG guidance (i.e., cessation of ablation upon a 30% reduction in the diaphragmatic compound motor action potential [CMAP] amplitude). The acute procedural endpoint was achieved in all dogs. Phrenic nerve injury was characterized by Wallerian degeneration, with subperineural injury to large myelinated axons and evidence of axonal regeneration. The degree of phrenic nerve injury paralleled the reduction in CMAP amplitude (P = 0.007). Animals randomized to EMG guidance had a lower incidence of acute hemi-diaphragmatic paralysis (50% vs 100%; P = 0.001), persistent paralysis at 30 days (21% vs 75%; multivariate odds ratio 0.12, 95% confidence interval [0.02, 0.69], P = 0.017), and a lesser severity of histologic injury (P = 0.001). Mature pulmonary vein ablation lesion characteristics, including circumferentiality and transmurality, were similar in both groups.Phrenic nerve injury induced by cryoballoon ablation is axonal in nature and characterized by Wallerian degeneration, with potential for recovery. An EMG-guided approach is superior to standard monitoring in limiting phrenic nerve damage.

The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation (STAR AF) trial compared 3 strategies for ablation of high-burden paroxysmal/persistent atrial fibrillation (AF): complex fractionated electrogram ablation (CFE), pulmonary vein isolation (PVI), or a combined approach (PVI with CFE). This subanalysis aimed to identify the effect on quality of life (QOL) conferred by ablation strategy, AF recurrence, and type of AF.The STAR AF study (n = 100) found 88%, 68%, and 38% freedom from AF30 seconds at 12 months for PVI with CFE, PVI, and CFE approaches, respectively (P = 0.001). QOL was measured before ablation and at 12 months after ablation using the Short-Form Health Survey (SF-36) scale. Transformed scores were calculated for each of the 8 subscales of the SF-36, and also converted to physical health and mental health component scores.There was a significant improvement in physical health (24%) and mental health (19%) component scores from baseline to 12 months after ablation (P0.05 for both). Significant QOL improvements were seen for all 3 ablation strategies despite differences in outcome. QOL measurements also improved regardless of AF recurrence, except in patients with an AF burden in the highest quartile (median 27.2 hours per month). AF recurrence independently predicted aggregate QOL score.QOL after AF ablation improves regardless of procedural outcome. QOL scores were only negatively affected in patients with a high symptomatic burden of arrhythmia recurrence suggesting that significant reduction in AF burden can improve QOL without total elimination of AF.

Aims Pacing from multiple sites in the left ventricle (LV) may bring about further resynchronization of the diseased heart compared with biventricular (BiV) pacing. We compared acute haemodynamic response (LV d P /d t max) of multisite and BiV pacing using a quadripolar LV lead. Methods and results In 21 patients receiving cardiac resynchronization therapy, a quadripolar LV lead and conventional right atrial and ventricular leads were connected to an external pacing system. A guidewire pressure sensor was placed in the LV for continuous d P /d t measurement. Four multisite pacing configurations were tested three times each and compared with BiV pacing using the distal LV electrode. Nineteen patients had useable haemodynamic data. Median increase in LV d P /d t max with BiV vs. atrial-only pacing was 8.2% (interquartile range 2.3%, 15.7%). With multisite pacing using distal and proximal LV electrodes, median increase in LV d P /d t max was 10.2% compared with atrial-only pacing (interquartile range 6.1%, 25.6%). In 16 of 19 patients (84%), two or more of the four multisite pacing configurations increased LV d P /d t max compared with BiV pacing. Overall, 72% of all tested configurations of multisite pacing produced greater LV d P /d t max than obtained with BiV pacing. Pacing from most distal and proximal electrodes was the most common optimal configuration, superior to BiV pacing in 74% of patients. Conclusion In the majority of patients, multisite pacing improved acute systolic function further compared with BiV pacing. Pacing with the most distal and proximal electrodes of the quadripolar LV lead most commonly yielded greatest LV d P /d t max.

Although hypertension is an established risk factor for atrial fibrillation (AF), the relationship between systolic blood pressure (SBP), mortality and hospitalizations has not been explored in a large cohort of patients with depressed vs preserved ejection fraction. We conducted a post-hoc

Background— Although the benefits of cardiac resynchronization therapy are well established in selected patients with heart failure and a prolonged QRS duration, salutary effects in patients with narrow QRS complexes remain to be demonstrated. Methods and Results— The Evaluation of Resynchronization Therapy for Heart Failure (LESSER-EARTH) trial is a randomized, double-blind, 12-center study that was designed to compare the effects of active and inactive cardiac resynchronization therapy in patients with severe left ventricular dysfunction and a QRS duration P =0.31]. Similarly, no significant differences were observed in left ventricular end-systolic volumes (−6.4 mL [95% CI, −18.8 to 5.9] versus 3.1 mL [95% CI, −9.2 to 15.5]; P =0.28) and ejection fraction (3.3% [95% CI, 0.7–6.0] versus 2.1% [95% CI, −0.5 to 4.8]; P =0.52). Moreover, cardiac resynchronization therapy was associated with a significant reduction in the 6-minute walk distance (−11.3 m [95% CI, −31.7 to 9.7] versus 25.3 m [95% CI, 6.1–44.5]; P =0.01), an increase in QRS duration (40.2 milliseconds [95% CI, 34.2–46.2] versus 3.4 milliseconds [95% CI, 0.6–6.2]; P Conclusions— In patients with a left ventricular ejection fraction ≤35%, symptoms of heart failure, and a QRS duration Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT00900549.