Single-chamber Versus Dual-chamber Implantable Cardioverter Defibrillators: Do We Need Physiologic Pacing in The Course?

Background: Many patients with ICD receive different antiarrhythmic drugs (e.g. sotalol, amiodarone, β-blockers) because of ventricular or atrial tachycardias. These drugs can cause AV-block or chronotropic incompetence resulting in a higher percentage of ventricular pacing. Methods: We analyzed in a retrospective study the impact of DDD(R) versus VVI(R) mode on subjective (NYHA classification) and objective parameters [brain natriuretic peptide (BNP), 6 minute walk test, echocardiography] in 12 of 120 patients (age 60.2 ± 11.2 years; 10 males, 2 females) who needed an upgrading of a single to a dual chamber ICD. The ICD had to be upgraded because of chronotropic incompetence in all patients with signs of progressing heart failure. Data were collected in VVI(R)-pacing and after 6 and 12 months in DDD(R)-pacing with a long AV-interval and AV hysteresis to reduce ventricular pacing. Results: The 6 minute walk test (392.4 ± 91.4 vs. 324.6 ± 93.3 m, P < 0.001), NYHA-classification (1.4 ± 0.3 vs. 2.6 ± 0.8, P < 0.0001), BNP (234.1 ± 73.5 vs. 410.4 ± 297.0 pg/ml, P < 0.001), left ventricular ejection fraction (49.8 ± 9.6 vs. 36.5 ± 10.9 %, P < 0.0001) and A-wave (73.6 ± 13.7 vs. 41.0 ± 14.0 cm/sec, P < 0.0001) improved with DDD(R)-pacing after 12 months. The ventricular pacing decreased (84.2 ± 18.1 vs. 1.1 ± 1.7 %, P < 0.0001) after 12 months by DDD(R)-pacing with long AV-interval (220.0 ± 10.4 ms) and AV hysteresis. Conclusion: Our data show a superiority of DDD(R) mode versus VVI(R) mode regarding subjective and objective parameters as NYHA-classification, BNP, 6 minute walk test, left ventricular ejection fraction and left ventricular endsystolic volume after 12 months. The improvements seem to depend on the reduction of ventricular pacing with advanced atrial contraction. But only a small number of patients needed the upgradation

Let\u27s Elope In An Aeroplane

https://digitalcommons.library.umaine.edu/mmb-vp/4739/thumbnail.jp

Nuclear fragmentation studies for microelectronic application

A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. Predicted results are compared to experiments with the surface barrier detectors of McNulty et al. The intranuclear cascade nuclear reaction model does not predict the McNulty experimental data for the highest energy events. A semiempirical nuclear cross section gives an adequate explanation of McNulty's experiments. Application of the formalism to specific electronic devices is discussed

Childhood and Adolescent Neighborhood Effects on Adult Income: Using Siblings to Examine Differences in Ordinary Least Squares and Fixed-Effect Models

Using sibling data from the Panel Study of Income Dynamics, this article examines the effects of child and adolescent neighborhood conditions on adult income. Estimates from fixed-effect models and ordinary least squares regression (OLS) models are compared at four stages of childhood development, with three important findings. First, OLS models that include extensive control variables do not necessarily overstate the effects of neighborhoods. Second, neighborhoods have both linear and nonlinear relationships with adult economic well-being. Third, neighborhoods exert effects on even the youngest children

Last resorts : a tour guide to territorial protection for the Republic of the Maldives

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 180-181).A two meter rise in sea levels projected by the end of this century threatens the sovereignty of the Maldivian nation state. While flight from the Maldives to establish a new homeland elsewhere has been proposed, the culture and economy of this country is inextricably entrenched in its geophysical environment. Although the Maldives is known for super luxury resorts, the nation's government is poorly positioned to defend a population of 400,000 people spread across 1200 islands. This thesis proposes a strategy by which the international resort operator, an autonomous and independently funded entity, can be mobilized as an agent of coastal defense. Also investigated are issues of artificial reef ecology, defensive coastal infrastructures, and prefabricated composite construction and modularity.by Buck Sleeper.M.Arch

SHCal04 Southern Hemisphere Calibration, 0–11.0 cal kyr BP

Recent measurements on dendrochronologically-dated wood from the Southern Hemisphere have shown that there are differences between the structural form of the radiocarbon calibration curves from each hemisphere. Thus, it is desirable, when possible, to use calibration data obtained from secure dendrochronologically-dated wood from the corresponding hemisphere. In this paper, we outline the recent work and point the reader to the internationally recommended data set that should be used for future calibration of Southern Hemisphere ¹⁴C dates