Electrocardiographic localization of the site of origin of ventricular tachycardia in patients with prior myocardial infarction

AbstractThe utility of the 12 lead electrocardiogram (ECG) in identifying the site of origin of sustained ventricular tachycardia in patients with previous myocardial infarction was studied. A new mapping grid, based on biplanar fluoroscopic imaging of the heart, was utilized for the definition of left ventricular endocardial sites. On the basis of QRS configurations resulting from left ventricular endocardial pacing at disparate sites in 22 patients (Group I), ECG features that were specific for particular sites were identified and used to construct an algorithm. Apical and basal sites were differentiated by the QRS configuration in leads V4 and aVR, anterior and inferior sites by that in leads III III and V6 and septal and lateral sites were differentiated using leads I, aVL and V1.The algorithm was used to predict the site of earliest endocardial activation during 44 episodes of sustained ventricular tachycardia in a second group of 42 patients (Group II) in a blinded fashion. Anterior sites were correctly predicted in 83% of cases, inferior sites in 84%, septal sites in 90% and lateral sites in 82% of cases. Apical and basal sites were each correctly predicted in 70% of cases, whereas intermediate sites were less well predicted (29 to 55%) on the basis of QRS configuration. Precise localization of the site of origin of ventricular tachycardia (in all three planes) was achieved in 17 cases (39%), and in 16 cases (36%) the site of origin was immediately adjacent to the predicted site.Prediction of the site of origin of ventricular tachycardia from the 12 lead ECG may serve as a useful, time-saving adjunct to, but not a substitute for, activation sequence mapping during ventricular tachycardia

Associational culture and the shaping of place: civic societies in Britain before 1960

We currently know civic societies as a widespread part of the amenity lobby, yet their history is little explored. Focusing on the emergence and growth of civic societies before 1960, this article examines some of that history. The first section provides a background context, linking civic groups to shifting ideas about architecture and space, and to reform movements of the nineteenth century. The second section explores the growth in numbers of associations and their memberships. The third section develops a discussion of the ideas and activities of societies, focusing particularly on their articulation of social and spatial interconnection, their use of a prescriptive urban aesthetic and their political influence

Written in the skies:advertising, technology, and modernity in Britain since 1885

New technologies significantly increased the reach of advertising from the late nineteenth century. Some aspects of this phenomenon, such as advances in printing methods, are well-known; others, in particular its controversial leap into the sky, have received far less attention. Though no longer seen as the home of divine portents, the sky did not become “empty space” in the modern era: it was still freighted with significance. This meant that the various attempts made by entrepreneurs from the 1880s to bring advertising to the skies were often met with hostility, even panic. In exploring these responses, this article resists depicting opponents of aerial advertising as over-sensitive aesthetes or technophobes. Rather, it explores the ways in which urbanization and commercial development imbued the sky with new meanings. The sky was imagined as man’s most valuable connection to nature in an urban society, a precious but endangered part of the nation’s heritage, and an essential counterweight to consumer society. Aerial advertising therefore represented an unjustifiable commercialization of a priceless public space. The rejection of this form of advertising did not involve denying modernity, but achieving an accommodation with it

Circular box C/D RNAs in Pyrococcus furiosus

Box C/D RNAs are small, noncoding RNAs that function in RNA modification in eukaryotes and archaea. Here, we report that box C/D RNAs exist in the rare biological form of RNA circles in the hyperthermophilic archaeon Pyrococcus furiosus. Northern analysis of box C/D RNAs reveals two prominent RNA species of different electrophoretic mobilities in total P. furiosus RNA preparations. Together, the results of Northern, ribozyme, RT-PCR, and lariat debranching analyses indicate that the two species are circular and linear RNAs of similar length and abundance. It seems that most, if not all, species of box C/D RNAs exist as circles in P. furiosus. In addition, the circular RNAs are found in complexes with proteins required for box C/D RNA function. Our finding places box C/D RNAs among the extremely few circular RNAs known to exist in nature. Moreover, the unexpected discovery of circular box C/D RNAs points to the existence of a previously unrecognized biogenesis pathway for box C/D RNAs in archaea