RT-80
|
Tachycardia induced atrial
fibrillation. Clinical usefulness of radiofrequency ablation of the triggering arrhythmia
|
|
|
Pietro Delise, Leonardo Coro,
Pietro Scipione, Mauro Fantinel.
Operative Unit of Cardiology, Hospital of Feltre (BL), Italy
|
|
Abstract
|
|
Atrial fibrillation in most patients initiates as a
primary arrhythmia or follows an atrial premature beat occurring during atrial vulnerable
period. In other patients atrial fibrillation results from the degeneration of another
supraventricular tachycardia, a phenomenon E.N. Pristowsky referred to as
tachycardia-induced tachycardia. A number of supraventricular tachycardias can trigger
atrial fibrillation: focal atrial tachycardia, common and uncommon atrial flutter,
atrioventricular reentrant tachycardia (related to an overt or a concealed Kent bundle)
and atrioventricular nodal reentrant tachycardia.
Recently it has been suggested that in some patients the elimination of the triggering
arrhythmia by radiofrequency catheter ablation is able to prevent also atrial
fibrillation. Unfortunatly the diagnosis of tachycardia-induced atrial fibrillation is not
always easy and in many cases the existence of a second supraventricular arrhythmia in
addition to atrial fibrillation is ignored. Finally the association of a supraventricular
tachycardia and atrial fibrillation not always means that the former is the trigger of the
latter. Therefore not always the ablation of the former arrhythmia is able to eliminate
also atrial fibrillation.
In patients with both atrial recurrent extrasistoles and atrial fibrillation the
ablation of the automatic focus can prevent atrial fibrillation. In patients with common
and uncommon atrial flutter radiofrequency ablation of subeustachian atrial isthmus is
able to prevent atrial flutter in about 80-90% of cases. However 10-27% of patients who
have only atrial flutter before ablation, after successful ablation present with episodes
of atrial fibrillation not previously documented. In addition patients with both
documented atrial flutter and atrial fibrillation recurrent atrial fibrillation is
reported in 50-89% after successful ablation of atrial flutter. In patients with overt
(WPW) or concealed Kent bundles the ablation of the anomalous pathway generally eliminates
all arrhythmias. In patients with both atrioventricular nodal reentrant tachycardia and
atrial fibrillation catheter ablation of the slow or fast pathway is able to eliminate
both arrhythmias in subjects without structural heart abnormalities. In patients with
structural heart abnormalities despite the cure of atrioventricular nodal tachycardia
atrial fibrillation care relapse. In the latter cases however antiarrhythmic drugs can
reduce or abolish paroxysmal palpitations.
|
Key Words
|
|
Atrial fibrillation
tachycardia induced atrial fibrillation, radiofrequency catheter ablation, role of
supraventricular tachycardias, clinical implications, R
|
