Are plasma natriuretic peptide levels influenced by automatic pacemaker algorithms for ventricular pacing minimization?

Background: Automatic atrioventricular search hysteresis (AVSH) is designed to reduce the cumulative percentage of potentially deleterious right ventricular apical pacing (VP%) in dual-chamber pacemakers. We investigated whether minimizing VP% by AVSH can, in turn, reduce ventricular wall stretching/stress, as assessed by plasma concentrations of the amino-terminal fragment of the pro-B-type natriuretic peptide (NT-proBNP).

Methods: After dual-chamber pacemaker implantation in 81 patients (age: 69 ± 11 years; males: 55.

Reduction of right ventricular pacing with advanced atrioventricular search hysteresis: results of the PREVENT study.

Background: Right ventricular pacing predisposes to the development of heart failure and atrial fibrillation. Automatic atrioventricular search hysteresis (AVSH) is a commonly used strategy to decrease the percentage of right ventricular pacing (%VP) in patients without permanent AV block, but the results have not been optimal.

Methods: The randomized, crossover PREVENT study evaluated whether an enhanced AVSH with two new features can reduce %VP compared with standard AVSH.

Undetected malignancies of the breast: dynamic contrast-enhanced MR imaging at 1.0 T.

Purpose: To assess the prevalence and characteristics of malignant breast lesions not identified with magnetic resonance (MR) imaging.

Materials And Methods: Breast tissue specimens were obtained in 464 of 967 patients who had undergone dynamic gadolinium-enhanced T1-weighted fast low-angle shot three-dimensional MR imaging of both breasts. A comparison of sensitivity, specificity, and predictive values of the prospectively recorded findings of mammography, ultrasonography (US), and MR imaging with the histopathologic results was performed with receiver operating characteristic (ROC) curve analysis.

New determination of the electron's mass.

A new independent value for the electron's mass in units of the atomic mass unit is presented, m(e) = 0.000 548 579 909 2(4) u. The value is obtained from our recent measurement of the g factor of the electron in (12)C(5+) in combination with the most recent quantum electrodynamical (QED) predictions.