Circadian variability patterns predict and guide premature ventricular contraction ablation procedural inducibility and outcomes

Background Infrequent intraprocedural premature ventricular complexes (PVCs) may impede radiofrequency catheter ablation (RFA) outcome, and pharmacologic induction is unpredictable. Objective The purpose of this study was to determine whether PVC circadian variation could help predict drug response. Methods Consecutive patients referred for RFA with detailed Holter monitoring and frequent monomorphic PVCs were included. Patients were divided into 3 groups based on hourly PVC count relationship to corresponding mean heart rate (HR) during each of the 24 hours on Holter: fast-HR-dependent PVC (F-HR-PVC) type for a positive correlation (Pearson, P <.05), slow-HR-dependent PVC (S-HR-PVC) type for a negative correlation, and independent-HR-PVC (I-HR-PVC) when no correlation was found. Results Fifty-one of the 101 patients (50.5%) had F-HR-PVC, 39.6% I-HR-PVC, and 9.9% S-HR-PVC; 30.7% had infrequent intraprocedural PVC requiring drug infusion. The best predictor of infrequent PVC was number of hours with PVC count <120/h on Holter (area under the curve 0.80, sensitivity 83.9%, specificity 74.3%, for ≥2 h). Only F-HR-PVC patients responded to isoproterenol. Isoproterenol washout or phenylephrine infusion was successful for the 3 S-HR-PVC patients, and no drug could increase PVC frequency in the 12 I-HR-PVC patients. Long-term RFA success rate in patients with frequent PVCs at baseline (82.9%) was similar to those with infrequent PVC who responded to a drug (77.8%; P = .732) but significantly higher than for those who did not respond to any drug (15.4%; P <.0001). Conclusion A simple analysis of Holter PVC circadian variability provides incremental value to guide pharmacologic induction of PVCs during RFA and predict outcome. Patients with infrequent I-HR-PVC had the least successful outcomes from RF ablation

KB-Rank: efficient protein structure and functional annotation identification via text query

The KB-Rank tool was developed to help determine the functions of proteins. A user provides text query and protein structures are retrieved together with their functional annotation categories. Structures and annotation categories are ranked according to their estimated relevance to the queried text. The algorithm for ranking first retrieves matches between the query text and the text fields associated with the structures. The structures are next ordered by their relative content of annotations that are found to be prevalent across all the structures retrieved. An interactive web interface was implemented to navigate and interpret the relevance of the structures and annotation categories retrieved by a given search. The aim of the KB-Rank tool is to provide a means to quickly identify protein structures of interest and the annotations most relevant to the queries posed by a user. Informational and navigational searches regarding disease topics are described to illustrate the tool’s utilities. The tool is available at the URL http://protein.tcmedc.org/KB-Rank

ETUDE DE L'IMPLICATION DES LYMPHOCYTES T CD4 + ET CD8 + DANS LE DEVELOPPEMENT DE L'ARTHRITE EXPERIMENTALE AU COLLAGENE

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Complex influence of gonadotropins and sex steroid hormones on QT interval duration

International audienceQT interval duration is longer in women than in men. Sex steroid hormones have inconsistently been suggested to explain this difference. Implication of gonadotropins has never been studied.Objective:We here report the combined influence of sex steroid hormones and gonadotropins on QT interval duration in healthy subjects and patients with congenital adrenal hyperplasia (CAH) as a model of testosterone and progesterone overexpression.Design:Patients. Eighty four CAH patients (58 women) and 84 healthy subjects matched-paired for sex and age were prospectively included. Circulating concentrations of 17-OH-progesterone, progesterone, testosterone, estradiol, FSH and LH, were measured concomitantly to recording of a digitized electrocardiogram.Results:QTcFridericia(QTcF) was shorter in women with CAH than in control women (404±2 msec vs. 413±2.1 msec, p≤0.001). 17-OH-progesterone, progesterone, progesterone/estradiol ratio and total testosterone were higher in women with CAH than in women controls (p<0.05) whereas FSH was lower (p≤0.05). According to multivariable analysis in all women, progesterone/estradiol ratio (β=-0.33) and FSH levels (β=0.34) were related to QTcF (r=0.5, p<0.0001) with no influence of CAH or healthy status. QTcF was not different between CAH (404.7±3.7 msec) or healthy men (396±2.8 msec). For men, QTcF (r=0.48, p<0.01) was negatively related to free testosterone (β=-0.29) and positively to FSH levels (β=0.34).Conclusion:Cardiac repolarization is influenced by complex interactions between sex steroid hormones and gonadotropins depending on gender. Our results indicate that progesterone/estradiol ratio, in women, testosterone, in men, and FSH, in both genders, are major determinants of ventricular repolarization with opposite effects on QTc interval