Incidence and predictors of premature ventricular complexes following catheter ablation for atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and previous studies have focused on the epidemiology, mechanisms and risk factors for this global disease (Ryder and Benjamin 1999). Various studies have examined the mechanism, epidemiology, and risk factors for AF. One of the most common triggers for AF is believed to be premature atrial contractions (PACs) usually arising from the pulmonary veins of the left atrium, but the relationship between AF and premature ventricular complexes (PVCs) is not well understood. Studies investigating the triggers of premature beats in both the atria and ventricles are similar, so it is possible that treatment for one arrhythmia may affect the incidence of another. It is hypothesized that due to commonly shared mechanisms of triggered activity or automaticity between PACs and PVCs, and shared risk factors, that patients with AF undergoing treatment with catheter ablation may be prone to develop PVCs. OBJECTIVE: To investigate the incidence of clinically detected PVCs among patients undergoing catheter ablation for AF, and clinical predictors of PVC development in this cohort of patients. We also aim to evaluate if incident PVC detection is associated with recurrent AF following AF ablation in a cohort of 317 patients receiving treatment at a single academic medical center. METHODS: A total of 375 patients undergoing AF ablation from 2009-2012 were reviewed, and patients that underwent repeat ablations were excluded, yielding 317 patients for analysis. T-tests and Chi-squared analyses were used in univariate analyses to test for significance between characteristics of AF patients who did and did not develop PVCs. Kaplan-Meier analyses and Cox proportional hazards models were used for univariate and multivariate survival analyses, respectively, to assess the risks of incident PVC development. RESULTS: Of 317 patients with AF undergoing pulmonary vein isolation (PVI) ablation, 36.3% developed clinically detectable PVCs following ablation. A history of clinically evident PVC prior to catheter ablation for AF was associated with an 80% increase in risk of incident PVC development (HR=1.83, 95% CI 1.02-3.26, p=0.041). Additionally, a history of prior angioplasty, stent, or percutaneous coronary intervention (PCI) was associated with a 73% decreased risk of incident PVCs (HR=0.27, 95% CI 0.08-0.88, p=0.03). In patients with a history of PVC prior to ablation, or who developed PVCs after ablation, there was no significant difference in the risk of AF recurrence (HR=1.01, 95% CI 0.70-1.46, p=0.96; and HR=1.09, 95% CI 0.78-1.53, p=0.60, respectively). CONCLUSIONS: Over 1 in 3 patients develop clinically detected PVCs following catheter ablation. Predictors of incident PVC development include a history of PVC, whereas a history of angioplasty, stent, or PCI was associated with less incident PVC development. Furthermore, there was no significant association between both a history of PVC or incident PVC and risk of recurrent AF following ablation

Stoichiometric Homeostasis in Two Native and Two Invasive South Dakotan Grasses

Increased nutrient availability has been widely linked to the success of invasive plants, however a general mechanism explaining these observations is lacking. Stoichiometric homeostasis (H), which is the regulation of internal nutrient concentrations, has been used to explain changes in plant community diversity under alterations in nutrient availability. One hypothesis holds that plants with high regulation (larger H) decrease in abundance in nutrient enriched conditions but are stable in nutrient deficient and drought conditions, likely due to extensive root systems. Additionally, plants with low regulation (lower H) increase in abundance under nutrient enriched conditions but are sensitive to drought conditions. I tested the hypotheses that H would be higher in native grasses than in invasive grasses, that H would be modulated by environmental conditions, and that differences in H would be associated with differences in growth and biomass allocation. I calculated H and measured plant growth and growth traits in two native (Pascopyrum smithii and Elymus canadensis) and two invasive (Bromus inermis and Agropyron cristatum) grasses grown in two experiments. Both experiments contained a range of N:P fertilizer supply concentrations and the first experiment contained a two-level drought treatment while the second experiment contained a two-level mycorrhizal inoculation treatment. In the first experiment, I found support for the hypothesis that H is higher in native than invasive plants, that environmental conditions (i.e. water availability) affect the value of H, and that differences in H were associated with differences in growth. In the second experiment, there was no successful mycorrhizal inoculation, resulting in no differences in H between mycorrhizal treatment groups. There were significant differences in total growth between the second experiment native and invasive grasses, despite there being no significant differences in H. Differences in H values between control-treated grasses in the two experiments may be due to differences in greenhouse temperature and light conditions. These results show first, significant differences exist in H between invasive and native grasses, with invasive grasses expressing lower values of H, second, environmental conditions effect the expression of H, and third, that differences in the expression of H are matched by differences in growth

Aspectus and Affectus: Robert Grosseteste, Understanding and Feeling. Georgetown University,Washington, D.C. (USA), 30 March-1 April 2017

Report of the conference 'Aspectus and Affectus: Robert Grosseteste, Understanding and Feeling', held at Georgetown University,Washington, D.C. (USA), 30 March-1 April 2017

AMPDB: the Arabidopsis Mitochondrial Protein Database

The Arabidopsis Mitochondrial Protein Database is an Internet-accessible relational database containing information on the predicted and experimentally confirmed protein complement of mitochondria from the model plant Arabidopsis thaliana (http://www.ampdb.bcs.uwa.edu.au/). The database was formed using the total non-redundant nuclear and organelle encoded sets of protein sequences and allows relational searching of published proteomic analyses of Arabidopsis mitochondrial samples, a set of predictions from six independent subcellular-targeting prediction programs, and orthology predictions based on pairwise comparison of the Arabidopsis protein set with known yeast and human mitochondrial proteins and with the proteome of Rickettsia. A variety of precomputed physical–biochemical parameters are also searchable as well as a more detailed breakdown of mass spectral data produced from our proteomic analysis of Arabidopsis mitochondria. It contains hyperlinks to other Arabidopsis genomic resources (MIPS, TIGR and TAIR), which provide rapid access to changing gene models as well as hyperlinks to T-DNA insertion resources, Massively Parallel Signature Sequencing (MPSS) and Genome Tiling Array data and a variety of other Arabidopsis online resources. It also incorporates basic analysis tools built into the query structure such as a BLAST facility and tools for protein sequence alignments for convenient analysis of queried results

A comparison of university student and community gamblers: Motivations, impulsivity, and gambling cognitions

Abstract Background and aims The present study tested whether the associations among motivational, cognitive, and personality correlates of problem gambling severity differed across university student gamblers (n = 123) and gamblers in the general adult community (n = 113) Methods The participants completed a survey that included standardized measures of gambling motivation, gambling related cognitions, and impulsivity. The survey also asked participants to report the forms of gambling in which they engaged to test whether gambling involvement (number of different forms of gambling) was related to problem gambling severity. After completing the survey, participants played roulette online to examine whether betting patterns adhered to the gambler's fallacy. Results Gambling involvement was significantly related to problem gambling severity for the community sample but not for the student sample. A logistic regression analysis that tested the involvement, motivation, impulsivity and cognitive correlates showed that money motivation and gambling related cognitions were the only significant independent predictors of gambling severity. Adherence to the gambler's fallacy was stronger for students than for the community sample, and was associated with gambling related cognitions. Discussion The motivational, impulsivity and cognitive, and correlates of problem gambling function similarly in university student gamblers and in gamblers from the general adult community. Interventions for both groups should focus on the financial and cognitive supports of problem gambling

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The influence of the ligand chelate effect on iron-amine-catalysed Kumada cross-coupling

The performance of Fe-amine pre-catalysts in a representative Kumada reaction is inversely proportional to the lability of the chelate ligand.</p

It\u27s Not Just Ferguson: Missouri Supreme Court Should Consolidate the Municipal Court System

The Missouri Supreme Court\u27s unprecedented decision to take control of Ferguson\u27s Municipal Court was based primarily on issues raised during sustained protest following the killing of Mike Brown and reports published by ArchCity Defenders and the Department of Justice. These reports highlighted racial disparity in traffic stops, excessive revenue generation, and excessive warrants and arrests and confirmed the lived experiences of poor and Black people in St. Louis: there is a racially discriminatory and profit-driven approach to law enforcement made possible only by the collaborative efforts of local government, police, and courts. These condemned practices are not unique to Ferguson. Rather, many St. Louis municipalities are demonstrably worse than Ferguson with respect to the highlighted factors. And while there have been legal victories5 in the past year, new legislation,6 and the sustained efforts of the Black Lives Matter movement, the Supreme Com1 should seize the opportunity to bring meaningful and transformative change to the region by following the recommendation of the Ferguson Commission7, ArchCity Defenders, SLU Law Legal Clinics, Better Together, Missourians Organizing for Reform and Empowerment, and the Organization for Black Struggle: Order the consolidation of our 81 courts into a full-time, professional regional court system