Atrial Tachycardias Encountered in the Context of Catheter Ablation for Atrial Fibrillation Part II: Mapping and Ablation

Over the past decade, there has been an exponential increase in the number of catheter ablation procedures performed for atrial fibrillation (AF). While for paroxysmal AF, proximal pulmonary vein isolation is sufficient in the majority of cases, ablation of persistent and longstanding AF requires an extensive surgical-like procedure. This approach is correlated with a high rate of AF termination; however, this is achieved at the cost of at least one atrial tachycardia (AT) during the index procedure or during the patient's follow-up in the vast majority of cases. As these ATs are often multiple, complex, and frequently more symptomatic than AF, they constitute the last and frequently the most difficult step in ablation for patients with persistent AF. This review concentrates on the practical approaches to the treatment of AT in the context of AF ablation and provides an algorithm that aims at facilitating mapping and ablation strategies using conventional electrophysiological tools .     

游离植皮结合负压封闭引流技术治疗大面积皮肤缺损

目的探讨植皮后使用负压封闭引流(vacuum sealing drainage,VSD)敷料结合半透膜使植皮区均匀受压,充分引流,观察治疗大面积皮肤缺损的临床效果。方法对46例皮肤缺损的患者,有效清创,缺损区创面新鲜时,取刃厚皮片或中厚皮片,大块植皮后,VSD敷料结合半透膜覆盖,持续负压吸引,1周左右去除VSD敷料。结果44例患者植皮完全成活,2例患者去除VSD敷料后,边缘少许坏死,积极换药后成活,皮片功能均恢复正常。结论该手术方法操作简单,术后护理方便,是一种较理想的植皮方法。     

Serum measurement of interleukin‐31 (IL‐31) in paediatric atopic dermatitis: elevated levels correlate with severity scoring

Background Interleukin‐31 (IL‐31) is a novel T‐helper‐lymphocyte‐derived cytokine that plays an important role in human T‐cell‐mediated skin diseases. When overexpressed in transgenic mice, IL‐31 induces severe pruritus resembling eczema in humans. Serum IL‐31 was previously found overexpressed in adults with atopic dermatitis (AD). The novelty of this study is the use of a pediatric patient group as well as comparison of IL‐31 levels during flare and quiescence. Objective This case‐controlled longitudinal study was designed to determine the levels of IL‐31 in serum of AD children and its associations in relation to disease activity and severity. Methods Sera were obtained from 50 AD children and 40 healthy volunteers. IL‐31 levels were measured using a sandwich ELISA. All AD patients were followed up and re‐sampled for serum IL‐31 after clinical remission. Serum IL‐31 levels were correlated with AD disease activity and severity variables. Results Serum IL‐31 levels were significantly higher whether during AD flare [median, 1600; mean (SD) = 1457.8 ± 770.4 pg/mL] or quiescence (1040; 958.7 ± 419.5 pg/mL), than those in controls (220; 197.3 ± 91.9 pg/mL). Serum IL‐31 levels were significantly higher in the high disease severity group compared with the moderate or low severity group. Moreover, serum IL‐31 levels correlated positively with the calculated severity scores (LSS, SSS and SCORAD index). Conclusion The results of this study confirm the importance of IL‐31 in AD pathophysiology. Serum IL‐31 level is an objective reliable marker of AD severity in children. It may represent a novel target for antipruritic drug development.     

舒芬太尼对0.75%罗哌卡因蛛网膜下腔阻滞效应的影响

目的:观察舒芬太尼对0.75%罗哌卡因蛛网膜下腔阻滞效应的影响。方法:40例择期行下腹部以下手术患者(ASAⅠ～Ⅱ级)随机分成两组:Ⅰ组(n=20)的蛛网膜下腔用药为罗哌卡因22.5mg,Ⅱ组(n=20)为罗哌卡因22.5mg+舒芬太尼5μg。分别观察两组的蛛网膜下腔阻滞效应及相关的副反应。结果:两组之间的血流动力学指标及相关副反应均无统计学差异(P>0.05)。运动阻滞起效时间、达最大运动阻滞时间、最大Bromage分级、运动阻滞持续时间、感觉阻滞起效时间、镇痛向尾延伸时间、痛觉减退平面和痛觉消失平面均无明显差异(P>0.05)。而镇痛向头延伸时间、镇痛减退至T12时间、镇痛持续时间Ⅱ组均长于Ⅰ组(P<0.01)。结论:小剂量舒芬太尼可明显延长0.75%罗哌卡因蛛网膜下腔阻滞的感觉阻滞时间,且无明显副反应,适合于时间较长的下腹部及下肢手术的麻醉。     

Origin of Heat-Induced Accelerated Junctional Rhythm

Accelerated Junctional Rhythm. Introduction : The application of high-frequency current to the AV junctional area results in a temperature rise in the myocardium and may cause accelerated junctional rhythm (AJR). The aim of the study was to characterize heat-induced AJR in an in vitro animal model.
Methods and Results : Studies were performed in isolated perfused pig and rabbit hearts. Using a small heating probe, we could induce AJR from a discrete area located in the middle of the triangle of Koch, which was smaller than the area from which RF energy application could elicit AJR. Histology showed that the heat-sensitive area was located over, or close to, the compact AV node. It did not correspond with the areas where double potentials were found or with the site(s) of earliest atrial activation during VA conduction. Microelectrode recordings revealed that AJR arose in nodal-type cells. Heat increased the slope of the phase 4 depolarization and shortened the action potential duration. Two types of AJR were observed: the first one was regular and the second one showed irregularity in the intervals. Interaction of multiple foci and the presence of conduction block between the foci and the His bundle caused the irregularity of the His-His intervals during the second type of AJR.
Conclusion: AJR observed during heat and RF application in the AV nodal area results from the effect of heat on AV nodal cells with underlying pacemaker activity. The heat-sensitive area is located over, or very close to, the compact AV node.