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Jousset F Tenkorang J Vesin JM Pascale P Ruchat P Rollin AG Fromer M Narayan SM Pruvot E 《Journal of cardiovascular electrophysiology》2012,23(9):1003-1012
Kinetics of Atrial Repolarization Alternans. Introduction: Repolarization alternans (Re‐ALT), a beat‐to‐beat alternation in action potential repolarization, promotes dispersion of repolarization, wavebreaks, and reentry. Recently, Re‐ALT has been shown to play an important role in the transition from rapid pacing to atrial fibrillation (AF) in humans. The detailed kinetics of atrial Re‐ALT, however, has not been reported so far. We developed a chronic free‐behaving ovine pacing model to study the kinetics of atrial Re‐ALT as a function of pacing rate. Methods: Thirteen sheep were chronically implanted with 2 pacemakers for the recording of broadband right atrial unipolar electrograms and delivery of rapid pacing protocols. Beat‐to‐beat differences in the atrial T‐wave apex amplitude as a measure of Re‐ALT and activation time were analyzed at incremental pacing rates until the effective refractory period (ERP) defined as stable 2:1 capture. Results: Atrial Re‐ALT appeared intermittently but without periodicity, and increased in amplitude as a function of pacing rate until ERP. Intermittent 2:1 atrial capture was observed at pacing cycle lengths 40 ms above ERP, and increased in duration as a function of pacing rate. Episodes of rapid pacing‐induced AF were rare, and were preceded by Re‐ALT or complex oscillations of atrial repolarization, but without intermittent capture. Conclusion: We show in vivo that atrial Re‐ALT developed and increased in magnitude with rate until stable 2:1 capture. In rare instances where capture failure did not occur, Re‐ALT and complex oscillations of repolarization surged and preceded AF initiation. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1003‐1012, September 2012) 相似文献
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Purpose:National Accreditation Board for Hospitals and Healthcare Providers operates the health-care accreditation program in India. Research on impact of accreditation on eye-care centers is scarce. This article was conceptualized to scientifically evaluate the changes in documentation brought about by accreditation and its effects on staff in the Ophthalmology Department of an Indian Medical College.Methods:This was conducted as a quasi-experimental study in four steps. First, a point-based evaluation of case sheets in both pre-accreditation and postaccreditation phase, along with statistical analysis of the results, was done. Step two involved analysis of quality indicators and patient safety indices in successive years from inception of data to post-accreditation phase. Step three comprised a survey of staff employing a validated tool, and finally, face-to-face semistructured interviews with designated authorities, including finance departmental head, completed the study.Results:A statistically significant difference was seen in scores achieved by the pre and postaccreditation case sheets, with the postphase case sheets achieving 15% increased scores over the prephase case sheets. Quality indicator indices displayed improvements post-accreditation. There was an accompanying increase in quantity of documentation. Financial data analysis showed increased expenditure for accreditation under multiple heads. Staff believed that accreditation led to increased workload but did not express decreased satisfaction and felt that accreditation was eventually beneficial. However, staff believed rewards for improving quality can be enhanced.Conclusion:Accreditation increases quality and quantity of documentation, and staff workload. Increased financial costs also ensue.Staff believe that accreditation improves quality, is beneficial, but desire enhanced rewards. 相似文献
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Although accounting for 90 % of the intestinal surface area, small bowel adenocarcinomas are not common. The majority of these lesions are incidentally detected during laparotomy for intestinal obstruction or perforation. The symptoms associated with these lesions are not very specific and preoperative diagnosis is rare. We report two cases of jejunal adenocarcinomas detected in patients undergoing laparotomy for acute abdomen and review the literature for small bowel adenocarcinomas. 相似文献
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