Scaling of Aharonov-Bohm couplings and the dynamical vacuum in gauge theories

Recent results on the vacuum polarization induced by a thin string of magnetic flux lead us to suggest an analogue of the Copenhagen `flux spaghetti' QCD vacuum as a possible mechanism for avoiding the divergence of perturbative QED, thus permitting consistent completion of the full, nonperturbative theory. The mechanism appears to operate for spinor, but not scalar, QED.Comment: 11 pages, ITP-SB-92-40, (major conceptual evolution from original

Magnetic field-induced interactions between phones containing magnets and cardiovascular implantable electronic devices: Flip it to be safe?

BACKGROUND: Recent case reports and small studies have reported activation of the magnet-sensitive switches in cardiovascular implantable electronic devices (CIED) by the new iPhone 12 series, initiating asynchronous pacing in pacemakers and suspension of anti-tachycardia therapies in ICDs. OBJECTIVE AND METHODS: We performed a prospective single-center observational study to quantify the risk of magnetic field interactions of the iPhone 12 with CIEDs. A representative model of each CIED series from all manufacturers was tested ex vivo. Incidence and minimum distance necessary for magnet mode triggering were analyzed in 164 CIED patients with either the front or the back of the phone facing the device. The magnetic field of the iPhone 12 was analyzed using a 3-axis hall probe. RESULTS: Ex vivo, magnetic interferences occurred in 84.6% with the back compared to 46.2% with the front of the iPhone 12 facing the CIED. In vivo, activation of the magnet-sensitive switch occurred in 30 CIED patients (18.3%; 21 pacemaker, 9 ICDs) when the iPhone 12 was placed in close proximity over the CIED pocket and the back of the phone was facing the skin. Multiple binary logistic regression analysis identified the implantation depth (95% confidence interval [CI], 0.02 to 0.24) as independent predictor of magnet-sensitive switch activation. CONCLUSION: Magnetic field interactions occur only in close proximity, and with precise alignment of the iPhone 12 and CIEDs. It is important to advise CIED patients to not put the iPhone 12 directly on the skin above the CIED. Further recommendations are not necessary

The DZHK research platform: maximisation of scientific value by enabling access to health data and biological samples collected in cardiovascular clinical studies

The German Centre for Cardiovascular Research (DZHK) is one of the German Centres for Health Research and aims to conduct early and guideline-relevant studies to develop new therapies and diagnostics that impact the lives of people with cardiovascular disease. Therefore, DZHK members designed a collaboratively organised and integrated research platform connecting all sites and partners. The overarching objectives of the research platform are the standardisation of prospective data and biological sample collections among all studies and the development of a sustainable centrally standardised storage in compliance with general legal regulations and the FAIR principles. The main elements of the DZHK infrastructure are web-based and central units for data management, LIMS, IDMS, and transfer office, embedded in a framework consisting of the DZHK Use and Access Policy, and the Ethics and Data Protection Concept. This framework is characterised by a modular design allowing a high standardisation across all studies. For studies that require even tighter criteria additional quality levels are defined. In addition, the Public Open Data strategy is an important focus of DZHK. The DZHK operates as one legal entity holding all rights of data and biological sample usage, according to the DZHK Use and Access Policy. All DZHK studies collect a basic set of data and biosamples, accompanied by specific clinical and imaging data and biobanking. The DZHK infrastructure was constructed by scientists with the focus on the needs of scientists conducting clinical studies. Through this, the DZHK enables the interdisciplinary and multiple use of data and biological samples by scientists inside and outside the DZHK. So far, 27 DZHK studies recruited well over 11,200 participants suffering from major cardiovascular disorders such as myocardial infarction or heart failure. Currently, data and samples of five DZHK studies of the DZHK Heart Bank can be applied for

Optimal heart failure therapy and successful cardioversion in heart failure patients with atrial fibrillation

BACKGROUND: Effectiveness, safety, and other factors associated with success of cardioversion (CV) of atrial fibrillation (AF) have not yet been evaluated in patients with reduced left ventricular ejection fraction. We studied 148 consecutive patients with left ventricular dysfunction (ejection fraction < or = 45%), who underwent electrical CV for AF in our department. The patients had New York Heart Association heart failure ranging from class II to IV. The overall CV success rate was 71%. We relied on univariate and multivariate regression and sought variables influencing success rate. Conversion success did not correlate with New York Heart Association class. Instead, we found that the greatest predictor was the degree of heart failure treatment. Patients receiving beta-blockers, angiotensin-converting enzyme inhibitors or angiotension receptor blockers, plus mineralocorticoid receptor blockers had the greatest chance for conversion success. Success was more likely in patients with coronary artery disease (91%) than in patients with nonischemic cardiomyopathy. CONCLUSIONS: Cardioversion is a safe and effective method for the restoration of sinus rhythm in patients with AF and reduced left ventricular ejection fraction. Our findings underscore the value of aggressive heart failure treatment before CV in patients with AF

Mutational analysis of the PITX2 and NKX2-5 genes in patients with idiopathic atrial fibrillation

Atrial fibrillation (AF) is the most frequently encountered arrhythmia in clinical practice. In a subgroup of patients, AF is regarded as idiopathic when no signs of structural heart disease or other causes of the arrhythmia can be identified during conventional clinical work-up. Recent studies have demonstrated that AF has a substantial genetic basis in a number of cases. The entire coding sequences, including intron-exon boundaries, of the genes PITX2 and NKX2-5 were screened for genetic variants by means of initial polymerase chain reaction followed by DNA sequencing in 96 patients with idiopathic AF. Although we detected a number of variants, our candidate gene approach did not result in identification of mutations associated with AF in the coding regions of PITX2 or NKX2-5 in our well characterized AF cohort

Variations in the human soluble epoxide hydrolase gene and recurrence of atrial fibrillation after catheter ablation

Background: Single nucleotide polymorphisms (SNPs) of EPHX2 alter sEH activity and are associated with increased [rs41507953 (K55R)] or reduced [rs751141 (R287Q)] cardiovascular risk via modulation of fibrosis, inflammation or cardiac ion channels. This indicates an effect on development and therapy response of AF. This study tested the hypothesis that variations in the EPHX2 gene encoding human soluble epoxide hydrolase (sEH) are associated with atrial fibrillation (AF) and recurrence of atrial fibrillation after catheter ablation. Methods and Results: A total of 218 consecutive patients who underwent catheter ablation for drug refractory AF and 268 controls were included. Two SNPs, rs41507953 and rs751141, were genotyped by direct sequencing. In the ablation group, holter recordings 3, 12 and 24months after ablation were used to detect AF recurrence. No significant association of the SNPs and AF at baseline was detected. In the ablation group, recurrence of AF occurred in 20% of the patients 12months after ablation and in 35% 24months after ablation. The presence of the rs751141 polymorphism significantly increased the risk of AF recurrence 12months (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.237 to 8.276, p=0.016) and 24months (OR: 6.076, 95% CI: 2.244 to 16.451, p<0.0001) after catheter ablation. Conclusion: The presence of rs751141 polymorphism is associated with a significantly increased risk of AF recurrence after catheter ablation. These results point to stratification of catheter ablation by genotype and differential use of sEH-inhibitory drugs in the future

Impact of COVID-19 on Cardiovascular Testing in the United States Versus the Rest of the World

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-U.S. institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p &lt; 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection