[New systems of mapping and navigation in electrophysiology]. / Nouveaux systèmes de cartographie et de navigation en électrophysiologie.

The indications of radiofrequency ablation of arrhythmias have considerably increased since the introduction of the technique in the early 1990s. Interventional rhythmologists now treat arrhythmias which are more and more complex by their mechanism. This requires accurate representation of the ablation catheter position and the integration of spatial and temporal data to identify the arrhythmogenic substrate. The systems of mapping and navigation developed over the last ten years are important tools for interventional rhythmologists. They are very useful for the identification of complex arrhythmogenic substrates which require "individualised" ablations in specific cases. The aim of this article is to review different systems of mapping, and/or navigation currently on the market and their principal characteristics without entering into the details of their use in interventional electrophysiology.

[The electrocardiogram in ventricular tachycardias]. / Electrocardiogramme des tachycardies ventriculaires.

The electrocardiogram, as much as the clinical examination, is a basic tool for the cardiologist. Technological advances have led to a certain lack of interest in learning to read the electrocardiogram, for which close analysis can allow precise diagnosis, notably in the field of cardiac rhythm disorders. This article concerns the electrocardiogram in ventricular tachycardias with two themes: differential diagnosis of wide QRS complex tachycardias and recognition of the site of origin of a ventricular tachycardia. "Fine" analysis of the electrocardiogram is not an intellectual "game". Actually, careful analysis of the 12 lead ECG allows exact and rapid diagnosis in a large majority of cases, distinguishing a ventricular tachycardia from a supraventricular tachycardia with conduction defect; the appropriate management can be selected without delay. At the same time, close reading of the electrocardiogram also allows the site of origin of a ventricular tachycardia to be recognised. Combining this information with elements of the patient's record can allow the arrhythmia to be related to a known pathology or to prompt a targeted aetiological investigation.

Decommissioning of a university research reactor.

The objective of the UCLA Boelter Reactor Decommissioning Project was the release of the Boelter reactor facility for unrestricted use. The facility included a 100 kW Argonaut type research reactor that operated from 1963 to 1985, providing general reactor research. The decommissioning was planned as a two-phase program. Phase I involved removal of the reactor core structure for better access and assessment of the biological shield. Phase II decommissioning activities included structural steel removal, activated concrete removal, process equipment pit piping dismantlement, and clean concrete removal. The final release survey of the Boelter reactor facility demonstrated that all areas satisfied the project's release criteria. The total person-Sv for the project was 3.87 x 10(-2) (3.87 person-rem), most of which was received during the structural steel and activated concrete removal tasks and the disassembly of the reactor core.