Long-term effects of catheter ablation for lone atrial fibrillation: progressive atrial electroanatomic substrate remodeling despite successful ablation

BackgroundWhether curative ablation can prevent progression of the atrial electroanatomic remodeling associated with atrial fibrillation (AF) is not known.ObjectiveThe purpose of this study was to determine whether successful radiofrequency ablation (RFA) of AF can prevent progression of the atrial substrate associated with AF.MethodsDetailed right atrial electroanatomic maps from 11 patients without apparent structural heart disease undergoing RFA of AF at baseline and ≥6 months following successful RFA were compared to 11 control patients undergoing electrophysiologic evaluation of supraventricular tachycardia. Bipolar voltage, conduction, effective refractory periods (ERPs), and signal complexity were assessed.ResultsAt baseline compared with the control group, the AF group demonstrated (1) lower voltage (P ConclusionPatients with lone AF demonstrate evidence of an abnormal atrial substrate at baseline compared to control patients without AF. This substrate does not appear to reverse even after successful catheter ablation. These findings may have implications for long-term outcomes of ablation and for timing of ablative intervention.Andrew W. Teh, Peter M. Kistler, Geoffrey Lee, Caroline Medi, Patrick M. Heck, Steven J. Spence, Joseph B. Morton, Prashanthan Sanders and Jonathan M. Kalma

Interface-Induced Phenomena in Magnetism.

This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes

Kaluza's Law and Secondary Stress

Kaluza’s law is a proposed restriction in the metre of Beowulf against the resolution of light-heavy sequences: words like cyning ‘king’ can only resolve and count as the equivalent of a single heavy syllable under more restricted circumstances than can words such as wudu ‘wood’. There has been debate about how to define these ‘restricted circumstances’, with many investigators claiming that this limitation holds only under ‘secondary stress’(sometimes broadened to include subordinated stress in general). This article reviews the operation of Kaluza’s law in Beowulf, arguing that the correct conditioning is the position immediately following a heavy syllable. The level of stress carried by the (non-)resolving sequence is irrelevant. A phonological explanation for this restriction may be that the resolution ideally produces bimoraic (light-light) units; accordingly, resolution of light-heavy sequences, which is anomalous from a typological and phonological perspective, is only permitted in word-initial position, or in metrical equivalents