Duration of heart failure and the risk of atrial fibrillation: different mechanisms at different times?

Chronic heart failure increases the risk of atrial fibrillation (AF), with the prevalence of AF paralleling the severity of heart failure.1 Factors that underlie this increased susceptibility to AF may include electrical, structural, and neurohumoral changes.2 In AF, it is recognized that atrial electrophysiological remodelling occurs and contributes to the perpetuation of the arrhythmia, most notably the decrease of effective refractory period (ERP) which predisposes to re-entry by shortening the wavelength. Does heart failure cause similar changes in atrial electrophysiology that predispose to the arrhythmia

Short communication. In vitro oocyte maturation and fertilization rates in the Spanish Lidia bovine breed

The Lidia bovine breed is the most successful cattle breed on the Iberian Peninsula, also considered a hallmark of Spanish tradition and image around the world. The aims of the study were to characterize the oocyte recovery rates and to evaluate the effect of two standard in vitro maturation protocols on oocyte maturation (cumulus expansion and nuclear maturation) and fertilization rates after in vitro fertilization in this breed. For this purpose, 261 ovaries from Lidia cows were processed obtaining 1,125 viable cumulus oocyte complexes (COCs). The oocyte recovery rate obtained (4.31 viable COCs per ovary) was lower than those described previously in other studied breeds. Maturation rates were evaluated in two different oocyte maturation media with (M1) and without (M2) hormonal supplementation. The percentage of COCs with expanded cumulus cells was significantly lower in M1 (74.35%) compared with M2 (82.25%). Metaphase II (MII) rates (67.75% in M1 and 73.18% in M2) were similar to previous studies in different cattle populations. M2 significantly improved the percentage of COCs with their cumulus cells expanded (p < 0.01) and nuclear maturation rates (p < 0.05), but it did not affect the fertilization percentages obtained in this experiment. In conclusion, our study suggests that oocytes of the Lidia cattle breed can be obtained, matured and fertilized following standard protocols previously used in other cattle breeds

Chromosomal numeric abnormalities on early bovine embryos derived from in vitro fertilization: effect of the oocyte quality, maturation environment and incubation time

Chromosomal aberrations are one of the major causes of embryo failures in the mammals. It is also been demonstrated that the occurrence of this kind of abnormalities is higher on in vitro produced (IVP) embryos. This study was conducted to investigate the effect of oocyte morphology and maturation conditions on chromosomal abnormality rates in bovine preimplantational embryos. To this end, 790 early cattle embryos derived from oocytes with different morphology and maturated in different conditions (maturation period: 24 h vs 36 h; maturation media: five different serum supplements in TCM-199) were cytogenetically evaluated in three sequential experiments. Rates of normal diploidy and abnormal haploidy, polyploidy and aneuploidy were determined in each embryo. Throughout all experiments, the rate of chromosomal abnormalities were significantly (p<0.05) influenced by the oocyte morphology and maturation conditions (maturation time and culture media). We find that a lower morphological quality is connected with high rates of numerical chromosome abnormalities (p<0.05). Moreover, we also find that polyploidy is associated with increased maturation time (p<0.01), whereas maturation media significantly (p<0.05) affected the rates of haploidy and polyploidy. In general, the use of ECS or FCS as serum supplements produced higher rates of chromosomal aberrations (p<0.05) compared to the other serum supplements. According to our results, we can conclude that morphological quality of oocytes and maturation conditions affect the chromosomal abnormality rates of the subsequent IVP cattle embryos

Biological and Health-promoting Activity of Vinification Byproducts Produced in Spanish Vineyards

Several by-products are produced in the Spanish agricultural system. Among them, fresh and vinifiedgrape skins represent an abundant source of phenols with a potential nutraceutical value. Fresh grape skinextracts (FGSE) and vinification of grape skin extracts (VGSE) obtained by a microwave-assisted methodhave been chemically and biologically characterised. Their role in the maintenance of genetic stabilitywas stated by in vivo genotoxic and antigenotoxic evaluations (Drosophilla melanogaster wing spot test), aswell as by their potential chemopreventive effect (in an HL60 in vitro model). Total phenolic, anthocyaninand resveratrol contents were chemically characterised in the two extracts, showing some qualitativedifferences. Both extracts and resveratrol were not mutagenic in the Drosophila somatic mutation andrecombination tests, and exerted antigenotoxic activities against hydrogen peroxide. They also showedcytotoxic activity to HL60 leukaemia cells, with an IC50 of 4.5μL/mL, 4.6μL/mL and 98μM respectively andinduced apoptotic internucleosomic fragmentation in the HL60 cell line

Treatment of Obstructive Sleep Apnea Reduces the Risk of Atrial Fibrillation Recurrence After Catheter Ablation

ObjectivesThe aim of this study was to examine the effect of continuous positive airway pressure (CPAP) therapy on atrial fibrillation (AF) recurrence in patients with obstructive sleep apnea (OSA) undergoing pulmonary vein isolation (PVI).BackgroundOSA is a predictor of AF recurrence following PVI. However, the impact of CPAP therapy on PVI outcome in patients with OSA is poorly known.MethodsAmong 426 patients who underwent PVI between 2007 and 2010, 62 patients had a polysomnography-confirmed diagnosis of OSA. While 32 patients were “CPAP users” the remaining 30 patients were “CPAP nonusers.” The recurrence of any atrial tachyarrhythmia, use of antiarrhythmic drugs, and need for repeat ablations were compared between the groups during a follow-up period of 12 months. Additionally, the outcome of patients with OSA was compared to a group of patients from the same PVI cohort without OSA.ResultsCPAP therapy resulted in higher AF-free survival rate (71.9% vs. 36.7%; p = 0.01) and AF-free survival off antiarrhythmic drugs or repeat ablation following PVI (65.6% vs. 33.3%; p = 0.02). AF recurrence rate of CPAP-treated patients was similar to a group of patients without OSA (HR: 0.7, p = 0.46). AF recurrence following PVI in CPAP nonuser patients was significantly higher (HR: 2.4, p < 0.02) and similar to that of OSA patients managed medically without ablation (HR: 2.1, p = 0.68).ConclusionsCPAP is an important therapy in OSA patients undergoing PVI that improves arrhythmia free survival. PVI offers limited value to OSA patients not treated with CPAP

Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Assessment of Substrate for Ventricular Tachycardia With Hemodynamic Compromise.

Background: The majority of data regarding tissue substrate for post myocardial infarction (MI) VT has been collected during hemodynamically tolerated VT, which may be distinct from the substrate responsible for VT with hemodynamic compromise (VT-HC). This study aimed to characterize tissue at diastolic locations of VT-HC in a porcine model. Methods: Late Gadolinium Enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging was performed in eight pigs with healed antero-septal infarcts. Seven pigs underwent electrophysiology study with venous arterial-extra corporeal membrane oxygenation (VA-ECMO) support. Tissue thickness, scar and heterogeneous tissue (HT) transmurality were calculated at the location of the diastolic electrograms of mapped VT-HC. Results: Diastolic locations had median scar transmurality of 33.1% and a median HT transmurality 7.6%. Diastolic activation was found within areas of non-transmural scar in 80.1% of cases. Tissue activated during the diastolic component of VT circuits was thinner than healthy tissue (median thickness: 5.5 mm vs. 8.2 mm healthy tissue, p < 0.0001) and closer to HT (median distance diastolic tissue: 2.8 mm vs. 11.4 mm healthy tissue, p < 0.0001). Non-scarred regions with diastolic activation were closer to steep gradients in thickness than non-scarred locations with normal EGMs (diastolic locations distance = 1.19 mm vs. 9.67 mm for non-diastolic locations, p < 0.0001). Sites activated late in diastole were closest to steep gradients in tissue thickness. Conclusions: Non-transmural scar, mildly decreased tissue thickness, and steep gradients in tissue thickness represent the structural characteristics of the diastolic component of reentrant circuits in VT-HC in this porcine model and could form the basis for imaging criteria to define ablation targets in future trials

Antigenotoxicidad y citotoxicidad de alimentos

Los alimentos de origen vegetal son unos firmes candidatos para ser considerados como alimentos funcionales y jugar un papel en prevención y tratamiento de enfermedades degenerativa. Se han estudiado aceites de uso alimentario y esenciales, bebidas, plantas medicinales, plantas de consumo como Borago officinalis, Brassica carinata o Raphanus sativus cuya capacidad para acumular metales es bien conocida, y ciertos componentes activos de los alimentos citados. Se ha utilizado el sistema de Mutaciones y Recombinaciones Somáticas en células en proliferación de discos imaginales alares de Drosophila melanogaster (SMART) para determinar su seguridad alimentaria así como su papel en la protección del daño de ADN. Al mismo tiempo se analiza la potencia tumoricida en líneas celulares promielocíticas humanas (HL- 60) de las sustancias que previamente han sido detectadas como antimutagénicas frente a genotoxinas de tipo oxidativo. Se relacionan las respuestas antimutagénicas y citotóxicas de las sustancias ensayadas con su contenido en fenoles, glucosinolatos e isotiocianato

Critical appraisal of technologies to assess electrical activity during atrial fibrillation: a position paper from the European Heart Rhythm Association and European Society of Cardiology Working Group on eCardiology in collaboration with the Heart Rhythm Society, Asia Pacific Heart Rhythm Society, Latin American Heart Rhythm Society and Computing in Cardiology

We aim to provide a critical appraisal of basic concepts underlying signal recording and processing technologies applied for (i) atrial fibrillation (AF) mapping to unravel AF mechanisms and/or identifying target sites for AF therapy and (ii) AF detection, to optimize usage of technologies, stimulate research aimed at closing knowledge gaps, and developing ideal AF recording and processing technologies. Recording and processing techniques for assessment of electrical activity during AF essential for diagnosis and guiding ablative therapy including body surface electrocardiograms (ECG) and endo- or epicardial electrograms (EGM) are evaluated. Discussion of (i) differences in uni-, bi-, and multi-polar (omnipolar/Laplacian) recording modes, (ii) impact of recording technologies on EGM morphology, (iii) global or local mapping using various types of EGM involving signal processing techniques including isochronal-, voltage- fractionation-, dipole density-, and rotor mapping, enabling derivation of parameters like atrial rate, entropy, conduction velocity/direction, (iv) value of epicardial and optical mapping, (v) AF detection by cardiac implantable electronic devices containing various detection algorithms applicable to stored EGMs, (vi) contribution of machine learning (ML) to further improvement of signals processing technologies. Recording and processing of EGM (or ECG) are the cornerstones of (body surface) mapping of AF. Currently available AF recording and processing technologies are mainly restricted to specific applications or have technological limitations. Improvements in AF mapping by obtaining highest fidelity source signals (e.g. catheter–electrode combinations) for signal processing (e.g. filtering, digitization, and noise elimination) is of utmost importance. Novel acquisition instruments (multi-polar catheters combined with improved physical modelling and ML techniques) will enable enhanced and automated interpretation of EGM recordings in the near future