La Réentrée: Mécanisme Principal des Tachyarythmies Cliniques de l'adulte

Reentry is the most frequent mechanism in clinical tachyarrhythmias. It is the result of an initiating event (extrasystole in general) occurring in a favorable arrhythmogenic substrate (repolarization heterogeneity, anisotropic conduction, etc.). We distinguish reentry occurring around an anatomical obstacle from that occurring around functional obstaCle. The latter comprises several types with various electrophysiological characteristics, documented primarily on experimental preparations (leading circle, anisotropic reentry, figure-of-8, spiral wave, phase-2 reentry). The presence of an excitable gap in the circuit of reentry allows to identify the role of reentry in human arrhythmias and makes them potentially sensitive to the methods of stimulation. Anti-arrhythmic drugs can act on reentry by inhibiting the initiating extrasystole and/or by modifying the characteristics of the circuit such as prolonging refractory period and decreasing conduction velocity. We will discuss the possibilities of clinical application of new concepts of reentry.