[Bidirectional ventricular tachycardias].
Bidirectional tachycardias are rare arrhythmias. Nevertheless in the sixties and seventies these arrhythmias prompted much work relating to their mechanism. Discussions about the supposed supra-ventricular origin of certain bidirectional tachycardias essentially rested on presumptive arguments based on electrocardiographic analysis. All the electrophysiological investigations which could be performed in tachycardia showed a ventricular origin. The current hypotheses concerning the electrophysiological mechanism favour non-unifocal mechanisms as well as a very diverse aetiology: an automatic focus, or the triggered activities being associated with alternating conduction, or re-entry between the left hemibranches. Although the classic context is of excess digitalis with advanced cardiopathy, readily in atrial fibrillation with a poor prognosis as a corollary, the most recent description of catecholergic ventricular tachycardias with the very characteristic appearance of bidirectional tachycardias justifies updating the understanding of these unusual tachycardias.
Service de cardiologie, hôpital Lariboisière, Paris. antoine.leenhardt@lrb.ap-hop-paris.fr
A
A
Leenhardt
F
F
Extramiana
P
P
Milliez
I
I
Denjoy
O
O
Thomas
M
M
Meddane
P
P
Dejode
B
B
Cauchemez
D004562:Electrocardiography; D004594:Electrophysiology; D006801:Humans; D017180:Tachycardia, Ventricular / Q000503:physiopathology*