bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Analysis of Cardiac Rhythms for Discriminating Atrial Fibrillation From Lethal Ventricular Arrhythmias
Authors: DeMazumder Deeptankar , Lake Douglas E. , Cheng Alan , Moss Travis J. , Guallar Eliseo , Weiss Robert G. , Jones Steven R. , Tomaselli Gordon F. , Moorman J. Randall 
Published: May 2013

Background—
Implantable cardioverter-defibrillators (ICDs), the first line of therapy for preventing sudden cardiac death in high-risk patients, deliver appropriate shocks for termination of ventricular tachycardia (VT)/ventricular fibrillation. A common shortcoming of ICDs is imperfect rhythm discrimination, resulting in the delivery of inappropriate shocks for atrial fibrillation (AF). An underexplored area for rhythm discrimination is the difference in dynamic properties between AF and VT/ventricular fibrillation. We hypothesized that the higher entropy of rapid cardiac rhythms preceding ICD shocks distinguishes AF from VT/ventricular fibrillation.

Methods and Results—
In a multicenter, prospective, observational study of patients with primary prevention ICDs, 119 patients received shocks from ICDs with stored, retrievable intracardiac electrograms. Blinded adjudication revealed shocks were delivered for VT/ventricular fibrillation (62%), AF (23%), and supraventricular tachycardia (15%). Entropy estimation of only 9 ventricular intervals before ICD shocks accurately distinguished AF (receiver operating characteristic curve area, 0.98; 95% confidence intervals, 0.93–1.0) and outperformed contemporary ICD rhythm discrimination algorithms.

Conclusions—
This new strategy for AF discrimination based on entropy estimation expands on simpler concepts of variability, performs well at fast heart rates, and has potential for broad clinical application.
Contemporary Outcomes of Supraventricular Tachycardia Ablation in Congenital Heart Disease
Authors: Ueda Akiko , Suman-Horduna Irina , Mantziari Lilian , Gujic Marko , Marchese Procolo , Ho Siew Yen , Babu-Narayan Sonya V. , Ernst Sabine 
Published: May 2013

Background—
Remote magnetic navigation–guided ablation with 3-dimensional (3D)-image integration could provide maximum benefit in patients with complex anatomy. We reviewed supraventricular tachycardia (SVT) ablation in adult patients with congenital heart disease to assess the contribution of these technologies.

Methods and Results—

One hundred fifty-four SVT ablation procedures (228 SVTs) using a 3D-electroanatomic mapping system in 116 adult patients with congenital heart disease (mean age, 41; 76 male) were classified into 3 groups: Group A, manual mapping/ablation (n=60 procedures); Group B, remote magnetic navigation–guided mapping/ablation with normal femoral vein access (49); and Group C, remote magnetic navigation–guided mapping/ablation with difficult access (45). Group A included simple anomalies with less SVTs. Group B comprised predominantly Fontan patients with more SVTs. Group C included more complex defects, such as intra-atrial baffle or interrupted inferior venous access, in which retrograde aortic and superior venous accesses were used exclusively with more frequent use of image integration (97.8%;
P
<0.001). Acute success was 91.5%, 83.7%, and 82.2%, respectively (
P
=0.370). In group C, fluoroscopy time was the shortest (median, 4.2 min;
P
<0.001) despite the longer procedure duration (median, 253 min;
P
<0.001). SVTs free rates were 80.4%, 82.4%, and 75.8%, respectively (
P
=0.787) during a mean 20-months follow-up period.

Conclusions—
The combination of remote magnetic navigation, 3D-image integration, and electroanatomic mapping system facilitated safe and feasible ablation with very low fluoroscopy exposure even in patients with complex anomalies.
Chronic Kidney Disease and Outcomes in Heart Failure With Preserved Versus Reduced Ejection Fraction
Authors: Smith David H. , Thorp Micah L. , Gurwitz Jerry H. , McManus David D. , Goldberg Robert J. , Allen Larry A. , Hsu Grace , Sung Sue Hee , Magid David J. , Go Alan S. 
Published: May 2013

Background—
There is scant evidence on the effect that chronic kidney disease (CKD) confers on clinically meaningful outcomes among patients with heart failure with preserved left ventricular ejection fraction (HF-PEF).

Methods and Results—

We identified a community-based cohort of patients with HF. Electronic medical record data were used to divide into HF-PEF and reduced left ventricular EF on the basis of quantitative and qualitative estimates. Level of CKD was assessed by estimated glomerular filtration rate (eGFR) and by dipstick proteinuria. We followed patients for a median of 22.1 months for outcomes of death and hospitalization (HF-specific and all-cause). Multivariable Cox regression estimated the adjusted relative-risk of outcomes by level of CKD, separately for HF-PEF and HF with reduced left ventricular EF. We identified 14 579 patients with HF-PEF and 9762 with HF with reduced left ventricular EF. When compared with patients with eGFR between 60 and 89 mL/min per 1.73 m
2
, lower eGFR was associated with an independent graded increased risk of death and hospitalization. For example, among patients with HF-PEF, the risk of death was nearly double for eGFR 15 to 29 mL/min per 1.73 m
2
and 7× higher for eGFR<15 mL/min per 1.73 m
2
, with similar findings in those with HF with reduced left ventricular EF.

Conclusions—
CKD is common and an important independent predictor of death and hospitalization in adults with HF across the spectrum of left ventricular systolic function. Our study highlights the need to develop new and effective interventions for the growing number of patients with HF complicated by CKD.
Perivascular Adipose Tissue Potentiates Contraction of Coronary Vascular Smooth Muscle
Authors: Owen Meredith Kohr , Witzmann Frank A. , McKenney Mikaela L. , Lai Xianyin , Berwick Zachary C. , Moberly Steven P. , Alloosh Mouhamad , Sturek Michael , Tune Johnathan D. 
Published: May 2013

Background—
This investigation examined the mechanisms by which coronary perivascular adipose tissue (PVAT)–derived factors influence vasomotor tone and the PVAT proteome in lean versus obese swine.

Methods and Results—

Coronary arteries from Ossabaw swine were isolated for isometric tension studies. We found that coronary (
P
=0.03) and mesenteric (
P
=0.04) but not subcutaneous adipose tissue augmented coronary contractions to KCl (20 mmol/L). Inhibition of Ca
V
1.2 channels with nifedipine (0.1 µmol/L) or diltiazem (10 µmol/L) abolished this effect. Coronary PVAT increased baseline tension and potentiated constriction of isolated arteries to prostaglandin F2α in proportion to the amount of PVAT present (0.1–1.0 g). These effects were elevated in tissues obtained from obese swine and were observed in intact and endothelium denuded arteries. Coronary PVAT also diminished H
2
O
2
-mediated vasodilation in lean and, to a lesser extent, in obese arteries. These effects were associated with alterations in the obese coronary PVAT proteome (detected 186 alterations) and elevated voltage-dependent increases in intracellular [Ca
2+
] in obese smooth muscle cells. Further studies revealed that the Rho-kinase inhibitor fasudil (1 µmol/L) significantly blunted artery contractions to KCl and PVAT in lean but not obese swine. Calpastatin (10 μmol/L) also augmented contractions to levels similar to that observed in the presence of PVAT.

Conclusions—

Vascular effects of PVAT vary according to anatomic location and are influenced by an obese phenotype. Augmented contractile effects of obese coronary PVAT are related to alterations in the PVAT proteome (eg, calpastatin), Rho-dependent signaling, and the functional contribution of K
+
and Ca
V
1.2 channels to smooth muscle tone.
Shared Leadership in Multiteam Systems
Authors: Bienefeld Nadine , Grote Gudela 
Published: May 2013

Objective: In this study, we aimed to examine the effect of shared leadership within and across teams in multiteam systems (MTS) on team goal attainment and MTS success. Background: Due to different and sometimes competing goals in MTS, leadership is required within and across teams. Shared leadership, the effectiveness of which has been proven in single teams, may be an effective strategy to cope with these challenges. Method: We observed leadership in 84 cockpit and cabin crews that collaborated in the form of six-member MTS aircrews ( N = 504) during standardized simulations of an in-flight emergency. Leadership was coded by three trained observers using a structured observation system. Team goal attainment was assessed by two subject matter experts using a checklist-based rating tool. MTS goal attainment was measured objectively on the basis of the outcome of the simulated flights. Results: In successful MTS aircrews, formal leaders and team members displayed significantly more leadership behaviors, shared leadership by pursers and flight attendants predicted team goal attainment, and pursers’ shared leadership across team boundaries predicted cross-team goal attainment. In cockpit crews, leadership was not shared and captains’ vertical leadership predicted team goal attainment regardless of MTS success. Conclusion: The results indicate that in general, shared leadership positively relates to team goal attainment and MTS success, whereby boundary spanners’ dual leadership role is key. Application: Leadership training in MTS should address shared rather than merely vertical forms of leadership, and component teams in MTS should be trained together with emphasis on boundary spanners’ dual leadership role. Furthermore, team members should be empowered to engage in leadership processes when required.
Force-on-Force Handgun Practice
Authors: Taverniers John , De Boeck Pieter 
Published: May 2013

Objective: The aim of this study was to explore human factors aspects of reality-based “force-on-force” (FoF) handgun practice through a within-subjects field experiment that assessed subjective stress measurements, biomarker regulation, performance outcomes, and behavioral adaptations. Background: FoF handgun practice is a recent training asset for armed officers whereby dynamic opponents may act, react, and even retaliate with specially designed marker ammunition. Predesigned scenarios enable trainees to practice in a simulated real-life environment. Method: A sample of experienced military personnel ( N = 20) ran a handgun workshop in two conditions: FoF practice and traditional cardboard-target practice. Intra-individual assessments included anticipated distress, subjective stress, salivary alpha-amylase (sAA), shooting accuracy, and directly observable training seriousness. Results: Compared with the standard cardboard practice condition, FoF exposure caused significant increases in anticipatory distress, subjective stress, and sAA secretion. Furthermore, participants’ first encounter with FoF practice (vs. cardboard practice) substantially degraded their shooting performance and had a significant positive impact on the earnestness with which they approached their mission during the workshop. Conclusion: FoF practice is an effective training tool for armed officers because it simulates a realistic work environment by increasing task-specific stress such that it affects important outcomes of professional performance and leads to desirable behavioral changes during training. Application: Potential applications of this research include the introduction of biomarker assessments in human factors research and the design, based on reality-based practice, of effective training procedures for high-reliability professionals.
Neurostimulation in cluster headache: A review of current progress
Authors: Pedersen Jeppe L , Barloese Mads , Jensen Rigmor H 
Published: May 2013

Purpose of review Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide an overview of the rationale, methods and progress for each of these. Latest findings Results from a randomized, controlled trial investigating sphenopalatine ganglion stimulation have just been published. Reportedly the surgery is relatively simple and it is apparently the only therapy that provides relief acutely. Summary The rationale behind these therapies is based on growing evidence from clinical, hormonal and neuroimaging studies. The overall results are encouraging, but unfortunately not all patients have benefited. All the mentioned therapies require weeks to months of stimulation for a prophylactic effect to occur, suggesting brain plasticity as a possible mechanism, and only stimulation of the sphenopalatine ganglion has demonstrated an acute, abortive effect. Predictors of effect for all modes of neurostimulation still need to be identified and in the future, the least invasive and most effective strategy must be preferred as first-line therapy for intractable chronic cluster headache.
The Association of Prenatal Media Marketing Exposure Recall with Breastfeeding Intentions, Initiation, and Duration
Authors: Zhang Yuanting , Carlton Ewa , Fein Sara B. 
Published: May 2013

Background: Infant formula marketing, either directly to consumers or through health care providers, may influence women’s breastfeeding intentions, initiation, and duration. However, little is known about the impact of different types of media marketing on infant feeding intentions and behavior. Objective: This study investigated whether different types of recalled prenatal media marketing exposure to formula and breastfeeding information are related to breastfeeding intentions and behavior. Methods: Data were from the Infant Feeding Practices Study II, a longitudinal study from pregnancy through the infants’ first year. Sample sizes ranged from 1384 to 2530. Negative binomial, logistic regression, and survival models were used to examine associations between recalled prenatal exposure to formula or breastfeeding information and breastfeeding intentions and behavior. Results: Exposure to infant formula information from print media was associated with shorter intended duration of exclusive breastfeeding, and formula information from websites was related to lower odds of both intended and actual initiation. Exposure to breastfeeding information from websites was related to higher odds of both intended and actual initiation and longer intended duration of any breastfeeding. Breastfeeding information from print media was associated with longer duration of any breastfeeding, but information from broadcast media was associated with shorter duration of any breastfeeding. Conclusion: Mothers who recall exposure to formula information from print or websites are more likely to intend to use formula or to intend to use formula earlier and are less likely to initiate breastfeeding than mothers who do not recall seeing such information.
Is Paternal Infant Care Associated with Breastfeeding? A Population-Based Study in Japan
Authors: Ito Jun , Fujiwara Takeo , Barr Ronald G. 
Published: May 2013

Background: One qualitative study has reported that more paternal infant care and housework contributed to the maintenance of breastfeeding. However, few studies have quantitatively investigated these relationships. Objective: This study aimed to examine the association of paternal involvement in infant care and housework with exclusive breastfeeding during the first 6 months of life. Methods: Data from a population-based birth cohort study in Japan, the Longitudinal Survey of Babies in the 21st Century, were analyzed. We extracted information on infants who were singletons, term, normal birth weight, and living with both parents (n = 39 742). The associations between degree of paternal involvement in infant care and housework (high, middle, low) and breastfeeding patterns (exclusive, partial, formula only) were analyzed using ordered logistic regression adjusted for covariates. Maternal anxiety about childrearing was considered as a mediator. Results: Compared with the low level of paternal infant care group, infants in the middle and high level groups were significantly less likely to have been breastfed (adjusted odds ratio: 0.90, 95% confidence interval [CI], 0.84-0.97; and 0.73, 95% CI, 0.67-0.79, respectively). In contrast, the amount of housework carried out by fathers was not associated with breastfeeding pattern. Maternal anxiety about childrearing did not attenuate the association between paternal infant care and breastfeeding. Conclusion: Paternal infant care was inversely associated with breastfeeding during the first 6 months of life. An additional intervention study about the importance of breastfeeding that aims to educate fathers who tend to involve themselves in infant care is needed.
Adaptive adjustment of the randomization ratio using historical control data
Authors: Hobbs Brian P , Carlin Bradley P , Sargent Daniel J 
Published: May 2013

Background Prospective trial design often occurs in the presence of ‘acceptable’ historical control data. Typically, these data are only utilized for treatment comparison in a posteriori retrospective analysis to estimate population-averaged effects in a random-effects meta-analysis. Purpose We propose and investigate an adaptive trial design in the context of an actual randomized controlled colorectal cancer trial. This trial, originally reported by Goldberg et al., succeeded a similar trial reported by Saltz et al., and used a control therapy identical to that tested (and found beneficial) in the Saltz trial. Methods The proposed trial implements an adaptive randomization procedure for allocating patients aimed at balancing total information (concurrent and historical) among the study arms. This is accomplished by assigning more patients to receive the novel therapy in the absence of strong evidence for heterogeneity among the concurrent and historical controls. Allocation probabilities adapt as a function of the effective historical sample size (EHSS), characterizing relative informativeness defined in the context of a piecewise exponential model for evaluating time to disease progression. Commensurate priors are utilized to assess historical and concurrent heterogeneity at interim analyses and to borrow strength from the historical data in the final analysis. The adaptive trial’s frequentist properties are simulated using the actual patient-level historical control data from the Saltz trial and the actual enrollment dates for patients enrolled into the Goldberg trial. Results Assessing concurrent and historical heterogeneity at interim analyses and balancing total information with the adaptive randomization procedure lead to trials that on average assign more new patients to the novel treatment when the historical controls are unbiased or slightly biased compared to the concurrent controls. Large magnitudes of bias lead to approximately equal allocation of patients among the treatment arms. Using the proposed commensurate prior model to borrow strength from the historical data, after balancing total information with the adaptive randomization procedure, provides admissible estimators of the novel treatment effect with desirable bias-variance trade-offs. Limitations Adaptive randomization methods in general are sensitive to population drift and more suitable for trials that initiate with gradual enrollment. Balancing information among study arms in time-to-event analyses is difficult in the presence of informative right-censoring. Conclusions The proposed design could prove important in trials that follow recent evaluations of a control therapy. Efficient use of the historical controls is especially important in contexts where reliance on preexisting information is unavoidable because the control therapy is exceptionally hazardous, expensive, or the disease is rare.
Atypical Presentation of Verrucous Carcinoma
Authors: Penera Keith E. , Manji Karim A. , Craig Alex B. , Grootegoed Rebecca A. , Leaming Troy R. , Wirth Garrett A. 
Published: May 2013

Verrucous carcinoma is a slow-growing lesion that is most often found on the weight-bearing surface of the foot and should be considered in the differential diagnosis for chronic nonhealing wounds in the diabetic neuropathic population. Accurate diagnosis may be difficult initially and often requires repeat histopathologic evaluation by an experienced pathologist. Verrucous carcinoma can invade deeper tissues; however, extension to bone is a rare occurrence. The authors present a case report of an atypical verrucous carcinoma on the dorsal aspect of the foot and a review of the literature. Studies suggest that multiple therapies exist and recurrence does occur; however, this is less likely with wide excision and more so with Mohs’ surgery. With a high clinical suspicion and thorough histopathologic exam, bone involvement and amputation may be avoided. Levels of Evidence: Therapeutic, Level IV
Absence of the Fourth Tendon of the Flexor Digitorum Brevis Muscle
Authors: Bernhard Andrew , Miller Josh , Keeler Jason , Siesel Kathy , Bridges Evan 
Published: May 2013

This study was undertaken to help confirm the percentages concerning the presence or absence of the flexor digitorum brevis muscle tendon to the fifth toe. We also hope to be able to determine the presence based on gender and nationality. It is known to be absent occasionally; however, there is no definitive study dedicated to its prevalence. Using a pool of 60 cadavers, 97 total feet were included in our analysis. Of these feet, 47 (48%) lacked a flexor digitorum brevis tendon to the fifth toe at all. Furthermore, 25 (26%) had notably small tendons to the fifth toe. The final 25 (26%) had what the researchers deemed present tendons. This information could be helpful in surgical planning, including tendon transfer techniques, and biomechanical evaluations. Further research would need to be conducted as this was a cadaveric study. Levels of Evidence: Cadaver/anatomy research, Level V
Body Mass Index and Achilles Tendonitis
Authors: Klein Erin E. , Weil Lowell , Weil Lowell Scott , Fleischer Adam E. 
Published: May 2013

Introduction. High body mass index (BMI) has been implicated as an etiologic agent in Achilles tendonitis (AT) and may contribute to poorer treatment outcomes. The purpose of this study was to better elucidate the role of BMI in both the development and treatment of AT. Methods. A matched case–control (1:1) study design was used. Matching criteria were age, gender, and year of presentation. Consecutive patients who presented with a diagnosis of AT between 2002 and 2011 at a single foot and ankle specialty clinic were identified. Patients who presented with other foot pain at the same clinic served as controls (CG). The AT group was further stratified into treatment responders and nonresponders. The main effect measure for both analyses was an adjusted odds ratio. Results. A total of 944 patients (472 AT; 472 CG) were included. AT patients had higher BMI than those in the CG (30.2 ± 6.5 vs 25.9 ± 5.3, P < .001). Overweight and obese patients were 2.6 to 6.6 times more likely than those with a normal BMI to present with Achilles tendonitis ( P < .001). There was also elevated risk of presenting with AT at higher BMI categories (Mantel–Haenszel χ2 = 8.074, P = .004). However, only age, not BMI, correlated with having failed conservative treatment among the AT group, with patients older than 65 years at the greatest risk (odds ratio = 2.4, 95% confidence interval = 1.5 to 4.1, P < .001). Conclusion. BMI plays a role in the development of AT but does not appear to influence patient response to conservative treatment. Levels of Evidence: Prognostic, Level II