An approach to noncavotricuspid isthmus dependent flutter.

摘要

The archetypical atrial macro-reentrant atrial arrhythmia is cavotricuspid isthmus dependent counterclockwise flutter. This arrhythmia is bounded posteriorly by the crista terminalisand anteriorly by the tricuspid annulus, and uses the cavotricuspid isthmus as a critical zone of slowed conduction that supports the reentrant mechanism. These features, together with recognition of the characteristic surface electrocardiogram, have served to facilitate the rapid recognition and evolution of a highly successful ablation strategy for the cure of this arrhythmia. Furthermore, electrocardiographicand mapping studies have identified that this isthmus of conduction could support such macro-reentry in either orientation, which could also be cured by the same ablation strategy. Increasingly, such macro-reentry can occur in any region of the atria in the presence of adequate conduction barriers that support the substrate for reentry, manifesting as sustained monornorphic regular atrial tachycardias that are occasionally referred to as type II or atypical flutters. These are noncavotricuspid isthmus dependent flutters and may occur in either the right, left, or both atria in patients with or without underlying structural heart disease. While such macro-reentrant flutters frequently develop following previous cardiac surgery or ablation (particularly of atrial fibrillation), they have also been observed to occur in the absence of prior intervention when arrhythmia is supported by spontaneous regions of conduction abnormalities or electrical silence. This article will focus on the clinical approach used for the mapping and ablation of atypical flutters at Hopital Cardologique du Haut-Leveque and the Universite Victor Segalen Bordeaux II, Bordeaux, France.