A Case of Acute Ventricular Capture Threshold Rise Associated with Flecainide Acetate

Antiarrhythmic agents may increase capture threshold, but this is rarely of clinical significance. Flecainide acetate, a class IC agent, is reported to have a significant effect on the myocardial capture threshold. In this presentation, we report the case of a 72-year-old male, with a previously implanted VVI pacemaker due to sick sinus syndrome, who was treated with flecainide acetate for paroxysmal atrial arrhythmia control. During the fifteenth day of treatment, an abrupt rise in the ventricular capture threshold with ventricular pacing failure was noted. The capture threshold decreased two days after discontinuation of flecainide acetate

A work breakdown structure that integrates different views in aircraft modification projects

The Work Breakdown Structure (WBS) defines the work scope of a project. The way a WBS is defined depends on the person and his/her viewpoint. The aircraft modification business carries out a great variety of projects. Although the core skills and tasks are similar, there are very few projects that are exact repetition of previous work. The reuse of information is difficult without a good structure to archive and manage project information. This paper presents an integrated WBS approach for managing the work scope in aircraft modification projects. The model is the result of an in-depth study and analysis of the working methods in an aircraft modification industrial company. This WBS is designed to incorporate the information needs and the views of the different functions involved in aircraft modification. It provides the structure for the reuse of information, such as cost and schedules, in the diverse range of aircraft modification projects. In this model, the top tiers of the WBS are configured from a pre-defined industry specific template. The lower tiers are defined with a flexible structure to support the different views of the knowledge users and providers in the project. The information need for all the life stages of the project is fully covered. The integrated WBS is being implemented in an enterprise wide computing solution that is used for cost estimating in the collaborating company. The same approach could be used to enhance knowledge reuse where there is a great diversity in project contracts

Renal size and cardiovascular risk in prepubertal children

Renal size is an important parameter for the evaluation and diagnosis of kidney disease and has been associated with several cardiovascular risk factors in patients with kidney failure. These results are however discordant and studies in healthy children are lacking. We aimed to study the association between renal size (length and volume) and cardiovascular risk parameters in healthy children. Clinical, analytical and ultrasound parameters [renal length, renal volume, perirenal fat and carotid intima-media thickness (cIMT)] were determined in 515 healthy prepubertal children (176 lean, 208 overweight and 131 obese). Renal length and volume associated significantly and positively with several anthropometric and cardiovascular risk parameters including cIMT and systolic blood pressure (SBP) (all p < 0.001). Renal length and volume associated with cIMT and SBP in all study subgroups, but these associations were predominant in obese children, in whom these associations were independent after adjusting for age, gender and BSA (all p < 0.05). In multivariate analyses in the study subjects as a whole, renal length was an independent predictor of cIMT (β = 0.310, p < 0.0001) and SBP (β = 0.116, p = 0.03). Renal size associates with cIMT and SBP, independent of other well-established cardiovascular risk factors, and may represent helpful parameters for the early assessment of cardiovascular risk in children.status: publishe

Effects of flecainide and quinidine on arrhythmogenic properties of Scn5a+/− murine hearts modelling the Brugada syndrome

Brugada syndrome (BrS) is associated with a loss of Na+ channel function and an increased incidence of rapid polymorphic ventricular tachycardia (VT) and sudden cardiac death. A programmed electrical stimulation (PES) technique assessed arrhythmic tendency in Langendorff-perfused wild-type (WT) and genetically modified (Scn5a+/−) ‘loss-of-function’ murine hearts in the presence and absence of flecainide and quinidine, and the extent to which Scn5a+/− hearts model the human BrS. Extra-stimuli (S2), applied to the right ventricular epicardium, followed trains of pacing stimuli (S1) at progressively reduced S1–S2 intervals. These triggered VT in 16 out of 29 untreated Scn5a+/− and zero out of 31 WT hearts. VT occurred in 11 out of 16 (10 μm) flecainide-treated WT and nine out of the 13 initially non-arrhythmogenic Scn5a+/− hearts treated with (1.0 μm) flecainide. Quinidine (10 μm) prevented VT in six out of six flecainide-treated WT and 13 out of the 16 arrhythmogenic Scn5a+/− hearts in parallel with its clinical effects. Paced electrogram fractionation analysis demonstrated increased electrogram durations, expressed as electrogram duration (EGD) ratios, with shortening S1–S2 intervals in arrhythmogenic Scn5a+/− hearts, and prolonged ventricular effective refractory periods (VERPs) in non-arrhythmogenic Scn5a+/− hearts. Flecainide increased EGD ratios in WT (at 10 μm) and non-arrhythmogenic Scn5a+/− hearts (at 1.0 μm), whereas quinidine (10 μm) reduced EGD ratios and prolonged VERPs in WT and arrhythmogenic Scn5a+/− hearts. However, epicardial and endocardial monophasic action potential recordings consistently demonstrated positive gradients of repolarization in WT, arrhythmogenic and non-arrhythmogenic Scn5a+/− hearts under all pharmacological conditions. Together, these findings demonstrate proarrhythmic effects of flecainide in WT and Scn5a+/− murine hearts that recapitulate its clinical effects. They further attribute the arrhythmogenic phenomena observed here to re-entrant substrates resulting from delayed epicardial activation despite an absence of transmural heterogeneities of repolarization, in sharp contrast to recent characterizations in ‘gain-of-function’ Scn5a+/Δ murine hearts modelling the long-QT(3) syndrome