Adjunctive low-voltage area ablation for patients with atrial fibrillation: An updated meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of adjunctive low-voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain. METHODS: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses. RESULTS: Our meta-analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67-0.88; p < .01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35-0.85; p < .01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38-0.86; p < .01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39-1.56; p = .49). CONCLUSIONS: Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF.

Ionic Conductive Cellulose Mats by Solution Blow Spinning as Substrate and a Dielectric Interstrate Layer for Flexible Electronics.

Renewable cellulose substrates with submicron- and nanoscale structures have revived interest in paper electronics. However, the processes behind their production are still complex and time- and energy-consuming. Besides, the weak electrolytic properties of cellulose with submicron- and nanoscale structures have hindered its application in transistors and integrated circuits with low-voltage operation. Here, we report a simple, low-cost approach to produce flexible ionic conductive cellulose mats using solution blow spinning, which are used both as dielectric interstrate and substrate in low-voltage devices. The electrochemical properties of the cellulose mats are tuned through infiltration with alkali hydroxides (LiOH, NaOH, or KOH), enabling their application as dielectric and substrate in flexible, low-voltage, oxide-based field-effect transistors and pencil-drawn resistor-loaded inverters. The transistors exhibit good transistor performances under operation voltage below 2.5 V, and their electrical performance is strictly related to the type of alkali ionic specie incorporated. Devices fabricated on K+-infiltrated cellulose mats present the best characteristics, indicating pure capacitive charging of the semiconductor. The pencil-drawn load resistor inverter presents good dynamic performance. These findings may pave the way for a new generation of low-power, wearable electronics, enabling concepts such as the "Internet of Things".

Calcium Channels in Postnatal Development of Rat Pancreatic Beta Cells and Their Role in Insulin Secretion.

Pancreatic beta cells during the first month of development acquire functional maturity, allowing them to respond to variations in extracellular glucose concentration by secreting insulin. Changes in ionic channel activity are important for this maturation. Within the voltage-gated calcium channels (VGCC), the most studied channels are high-voltage-activated (HVA), principally L-type; while low-voltage-activated (LVA) channels have been poorly studied in native beta cells. We analyzed the changes in the expression and activity of VGCC during the postnatal development in rat beta cells. We observed that the percentage of detection of T-type current increased with the stage of development. T-type calcium current density in adult cells was higher than in neonatal and P20 beta cells. Mean HVA current density also increased with age. Calcium current behavior in P20 beta cells was heterogeneous; almost half of the cells had HVA current densities higher than the adult cells, and this was independent of the presence of T-type current. We detected the presence of α1G, α1H, and α1I subunits of LVA channels at all ages. The Cav 3.1 subunit (α1G) was the most expressed. T-type channel blockers mibefradil and TTA-A2 significantly inhibited insulin secretion at 5.6 mM glucose, which suggests a physiological role for T-type channels at basal glucose conditions. Both, nifedipine and TTA-A2, drastically decreased the beta-cell subpopulation that secretes more insulin, in both basal and stimulating glucose conditions. We conclude that changes in expression and activity of VGCC during the development play an important role in physiological maturation of beta cells.

Trauma Eléctrico / Electrical trauma

El trauma eléctrico puede ocurrir por contacto con un cable eléctricamente activo o con un rayo, clasificándose elmismo en lesiones por bajo voltaje para aquellas de menos de 1000V y lesiones por alto voltaje para aquellas demás de 1000V. Posee una incidencia poco despreciable siendo una causa frecuente de lesión por un fenómenonatural. Diferentes factores entre ellos el tipo de corriente, la resistencia de los tejidos, la duración del contacto,el voltaje, y los factores ambientales definen la gravedad y extensión de las lesiones que produce. Los tejidosafectados con mayor frecuencia son los nervios, vasos, hueso, músculo y piel siendo prevalentes las quemaduras,arritmias, parestesias y otros daños a los sistemas nervioso y cardiovascular. A pesar de tener una mortalidadbaja, la lesión difusa causada por el trauma eléctrico deriva en una importante cantidad de secuelas a cortoy largo plazo que se presenta en un alto porcentaje de los sobrevivientes y que, debido a su sintomatologíainespecífica podría resultar difícil de identificar y diagnosticar.

Electric trauma can occur by contact with an active electric wire or a lightning, being classified in low-voltage injuriesfor those under 1000V and high- voltage injuries for those over 1000V. It has a little despicable incidence beinga frequent cause of injury from a natural phenomenon. Different factors including the type of current, resistanceof the tissues, duration of contact, voltage, and environmental factors determine the severity and extent of theinjuries that it produces. The tissues most commonly affected are the nerves, vessels, bones, muscle and skin beingprevalent the burns, arrhythmias, paresthesia, and other damages to the nervous and cardiovascular systems.Despite having a low mortality, diffuse injury caused by electric trauma results in an important amount of short andlong-term sequelae that occurs in a high percentage of the survivors, and because of its non-specific symptoms maybe difficult to identify and diagnose.

Resultados en el manejo de quemaduras eléctricas en un hospital de tercer nivel / Results in the management of electrical burns at a third level health care hospital

Objetivo: Demostrar si existe diferencia en los resultados del manejo de pacientes con quemaduras por electricidad de alto y bajo voltaje en el Antiguo Hospital Civil de Guadalajara y comparar nuestros resultados con lo publicado en la literatura. Sede: Antiguo Hospital Civil ''Fray Antonio Alcalde'' (tercer nivel de atención). Diseño: Estudio descriptivo y retrospectivo. Análisis estadístico: Para el análisis de variables no paramétricas se utilizó la prueba de χ² y para variables paramétricas la prueba t de Student, considerando estadísticamente significativo un valor de p ≤ a 0.05. Pacientes y métodos: Pacientes con quemaduras por electricidad en el periodo del 1 de enero del 2010 al 31 de diciembre del 2010. Se incluyeron todos los pacientes con quemaduras por electricidad y se dividieron en dos grupos: grupo I, pacientes con quemaduras por alto voltaje y grupo II, pacientes con quemaduras de bajo voltaje. Las variables estudiadas fueron edad, sexo, ocupación, estado civil, tipo de quemadura (alto o bajo voltaje), sitio de entrada, sitio de salida, tiempo entre la lesión y la llegada a urgencias, porcentaje de superficie corporal quemada, tratamiento establecido, volumen urinario, mioglobinuria, procedimientos quirúrgicos, días de estancia hospitalaria y mortalidad. Resultados: Se incluyeron un total de 22 pacientes adultos, 19 hombres y 3 mujeres. El grupo I incluyó 8 pacientes y el grupo II 14 pacientes. Todos los pacientes llegaron al servicio de urgencias dentro de las primeras 24 horas posteriores al accidente. Los pacientes con quemaduras por alto voltaje presentaron mayor estancia hospitalaria (p 0.0035). Se presentó únicamente una muerte, perteneciente al grupo I. Conclusión: Las quemaduras por alto voltaje confieren mayor morbimortalidad y mayor estancia hospitalaria.

Objective: To demonstrate whether there is a difference in the results of handling patients with high or low voltage-induced burns treated at the Antiguo Hospital Civil de Guadalajara and to compare our results with those in the literature. Setting: Antiguo Hospital Civil ''Fray Antonio Alcalde'' (third level health care hospital). Design: Descriptive, retrospective study. Statistical analysis: χ2 square test was used for non-parametric variables and Student's t test was used for parametric variables. Statistical significance was set at p ≤ than 0.05. Patients and methods: Patients with electrical burns cared for from January 1, 2010 to December 31, 2010. All patients with electrical burns were included and were divided in two groups: group I, those with high voltage burns, and group II those with low voltage burns. Variables studied were: age, sex, occupation, civil status, type of burn (high or low voltage), entrance site, exit site, time elapsed between injury and arrival to the emergency care, percentage of burnt body surface, established treatment, urinary volume, myoglobinuria, surgical procedures, days of in-hospital stay, and mortality. Results: A total of 22 adult patients were included, 19 men and 3 women. Group I consisted of 8 patients and group II of 14 patients. All patients arrived at the emergency ward within the first 24 hours after the accident. Patients with high-voltage burns had longer in-hospital stays (p 0.0035). There was only one death, pertaining to group I. Conclusion: High voltage burns lead to greater morbidity and mortality, and to a longer in-hospital stay.