Publications by authors named "Bradfield J"

Background: Ventricular tachycardia (VT) substrate characteristics before transcatheter pulmonary valve replacement (TPVR) in repaired tetralogy of Fallot (rTOF) are unknown.

Objectives: In this study, the authors sought to evaluate substrates for sustained monomorphic VT before TPVR in rTOF.

Methods: Retrospective (2017 to 2021) and prospective (commencing 2021) rTOF patients with native right ventricular outflow tract referred for electrophysiology study (EPS) before TPVR were included.

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We present the results of a GC-MS and UHPLC-MS analysis of residue recovered from the marrow cavity of a 7,000-year-old bovid femur from Kruger Cave, South Africa. The femur was filled with an unknown substance into which were embedded three bone arrowheads, indicating that the femur served as a quiver. Our results reveal the presence of digitoxin and strophanthidin, both cardiac glycosides associated with hunting poisons.

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Genetic effects on changes in human traits over time are understudied and may have important pathophysiological impact. We propose a framework that enables data quality control, implements mixed models to evaluate trajectories of change in traits, and estimates phenotypes to identify age-varying genetic effects in GWAS. Using childhood BMI as an example trait, we included 71,336 participants from six cohorts and estimated the slope and area under the BMI curve within four time periods (infancy, early childhood, late childhood and adolescence) for each participant, in addition to the age and BMI at the adiposity peak and the adiposity rebound.

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  • A large study with nearly 30,000 parent-offspring pairs from Norway identified a key genetic variant in UGT1A4 that reduces jaundice risk significantly.
  • The research shows different genetic factors influence neonatal jaundice compared to adult bilirubin levels, indicating unique genetic mechanisms at play.
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Declining student mental health is a global public health issue. Campus-based animal-assisted interventions (AAIs) are popular and effective interventions to prevent and alleviate symptoms. How to design, implement and evaluate evidence-based, student-centred interventions that enjoy sustained stakeholder buy-in and support is less known.

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  • A study was conducted to evaluate the success and outcomes of electroanatomical-guided cardioneuroablation (EACNA) in treating patients with vagally induced atrioventricular blocks (VAVBs).
  • The results showed a high acute procedural success rate of 96.2%, but 14% of patients experienced recurrence of AVB or new syncopal episodes during a follow-up period of approximately 300 days.
  • The findings suggest that EACNA is a promising option for patients with VAVB, but further research is needed to explore its effects on daytime symptom burden.
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  • Scientists looked at the timing of when girls start their periods (called menarche) and how it can affect their health later in life.
  • They studied about 800,000 women and found over a thousand genetic signals that influence when menstruation starts.
  • Some women have a much higher chance of starting their periods too early or too late based on their genetic makeup, suggesting that genes play a big role in this process!
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Background: Assessment of origin of ventricular tachycardias (VTs) arising from epicardial vs endocardial sites are largely challenged by the available criteria and etiology of cardiomyopathy. Current electrocardiographic (ECG) criteria based on 12-lead ECG have varying sensitivity and specificity based on site of origin and etiology of cardiomyopathy.

Objectives: This study sought to test the hypothesis that epicardial VT has a slower initial rate of depolarization than endocardial VT.

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The ch12q13 locus is among the most significant childhood obesity loci identified in genome-wide association studies. This locus resides in a non-coding region within FAIM2; thus, the underlying causal variant(s) presumably influence disease susceptibility via cis-regulation. We implicated rs7132908 as a putative causal variant by leveraging our in-house 3D genomic data and public domain datasets.

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Nutrition science has been criticised for its methodology, apparently contradictory findings and generating controversy rather than consensus. However, while certain critiques of the field are valid and informative for developing a more cogent science, there are also unique considerations for the study of diet and nutrition that are either overlooked or omitted in these discourses. The ongoing critical discourse on the utility of nutrition sciences occurs at a time when the burden of non-communicable cardiometabolic disease continues to rise in the population.

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Genetic effects on changes in human traits over time are understudied and may have important pathophysiological impact. We propose a framework that enables data quality control, implements mixed models to evaluate trajectories of change in traits, and estimates phenotypes to identify age-varying genetic effects in genome-wide association studies (GWASs). Using childhood body mass index (BMI) as an example, we included 71,336 participants from six cohorts and estimated the slope and area under the BMI curve within four time periods (infancy, early childhood, late childhood and adolescence) for each participant, in addition to the age and BMI at the adiposity peak and the adiposity rebound.

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Electrical impedance tomography (EIT) is medical imaging technique in which small electrical signals are used to map the electrical impedance distribution within the body. It is safe and non-invasive, which make it attractive for use in continuous monitoring or outpatient applications, but the high cost of commercial devices is an impediment to its adoption. Over the last 10 years, many research groups have developed their own EIT devices, but few designs for open-source EIT hardware are available.

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Article Synopsis
  • * It focuses on the CNA-FWRD Registry, a multicenter prospective study that compares outcomes between patients receiving standard therapy and those undergoing cardioneuroablation over a follow-up period of three years.
  • * The findings aim to provide valuable data on long-term effects, recurrence of symptoms, and overall safety of cardioneuroablation, addressing a gap in existing research which is largely based on retrospective studies.
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Background: Tetralogy of Fallot (TOF) is associated with risk for sustained monomorphic ventricular tachycardia (VT). Preemptive electrophysiology study before transcatheter pulmonary valve placement is increasing, but the value of MDCT for anatomical VT isthmus assessment is unknown.

Objectives: The purpose of this study was to determine the impact of multidetector computed tomography (MDCT) in the evaluation of sustained monomorphic VT for repaired TOF.

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Regions under balancing selection are characterized by dense polymorphisms and multiple persistent haplotypes, along with other sequence complexities. Successful identification of these patterns depends on both the statistical approach and the quality of sequencing. To address this challenge, at first, a new statistical method called LD-ABF was developed, employing efficient Bayesian techniques to effectively test for balancing selection.

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  • - This study explores how growth patterns during puberty relate to future health outcomes by analyzing height data from about 56,000 individuals across various ancestries using a technique called SITAR.
  • - The researchers identified 26 significant genetic loci linked to height growth during puberty and found that different growth rates are associated with various health risks, like type 2 diabetes and heart conditions.
  • - The findings suggest that there are multiple growth trajectories during puberty, each influencing adult health differently, indicating that no single growth pattern is the "best" for lifelong health outcomes.
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Background: Recurrent ventricular tachycardia (VT) after prior endocardial catheter ablation(s) presents challenges in the setting of prior cardiac surgery where percutaneous epicardial access may not be feasible.

Objective: The purpose of this study was to compare the outcomes of cryothermal vs radiofrequency ablation in direct surgical epicardial access procedures.

Methods: We performed a retrospective study of consecutive surgical epicardial VT ablation cases.

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Background: Cardioneuroablation (CNA) is an attractive treatment of vasovagal syncope. Its long-term efficacy and safety remain unknown.

Objective: The purpose of this study was to develop a chronic porcine model of CNA to examine the susceptibility to ventricular tachyarrhythmia (ventricular tachycardia/ventricular fibrillation [VT/VF]) and cardiac autonomic function after CNA.

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Pubertal timing varies considerably and has been associated with a range of health outcomes in later life. To elucidate the underlying biological mechanisms, we performed multi-ancestry genetic analyses in ~800,000 women, identifying 1,080 independent signals associated with age at menarche. Collectively these loci explained 11% of the trait variance in an independent sample, with women at the top and bottom 1% of polygenic risk exhibiting a ~11 and ~14-fold higher risk of delayed and precocious pubertal development, respectively.

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Sudden cardiac arrest (SCA) is the leading cause of death in young athletes. Despite efforts to improve preparedness for cardiac emergencies, the incidence of out-of-hospital cardiac arrests in athletes remains high, and bystander awareness and readiness for SCA support are inadequate. Initiatives such as designing an emergency action plan (EAP) and mandating training in cardiopulmonary resuscitation (CPR) and automated external defibrillator use (AED) for team members and personnel can contribute to improved survival rates in SCA cases.

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The detection of complex poison recipes applied to ancient hunting weapons has the potential to provide important insights into traditional pharmacological knowledge systems. Yet, recipes comprising many ingredients can be challenging to decipher, especially in older samples that have undergone biodegradation. We present the results of our attempt to analyze samples of poison collected from nineteenth and twentieth century arrowheads from southern Africa, and from a 1000-year-old archaeological bone point.

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