Sites of focal atrial activity characterized by endocardial mapping during atrial fibrillation.
OBJECTIVE
The aim of the present study was to assess the feasibility of identifying sites of focal atrial activity by localized high-density endocardial mapping during atrial fibrillation (AF).


BACKGROUND
Sites of focal activity in the left atrium have been demonstrated by epicardial mapping during AF.


METHODS
Twenty-four patients (15 with paroxysmal, 3 with persistent, and 6 with permanent AF) underwent endocardial mapping during AF. A 20-pole catheter with five radiating spines was used to map both atria for 30 s in each of 10 pre-determined segments. A focal activity was defined as > or =3 atrial cycles with activation spreading from center to periphery of the mapping catheter. Catheter ablation was performed independent of the mapping results.


RESULTS
Spontaneous focal activities were observed in 13 sites in the left atrium (9%; anterior 1, roof 2, posterior 6, inferior 4) in 12 patients (9 paroxysmal, 3 persistent). Focal activity was observed continuously (two sites) or intermittently (11 sites, median 5 episodes), and associated with shortening of the cycle length (from 183 +/- 33 ms to 172 +/- 29 ms; p < 0.05). The mean duration of an intermittent episode was 1.5 s (range 0.4 to 7.1 s). Atrial fibrillation terminated without ablation at the foci in all of 12 patients, but in 2 of them, re-initiated arrhythmia was successfully ablated at these foci. Nine of these 12 patients (75%) were arrhythmia-free without antiarrhythmic drugs during a follow-up period of 7.0 +/- 3.1 months.


CONCLUSIONS
Termination of AF without ablation at the sites of atrial focal activity suggests that this activity may be triggered by impulses originating from other regions, such as the pulmonary veins.
Takahashi
Yoshihide
Y
Hôpital Cardiologique du Haut-Lévêque-Université Victor Segalen Bordeaux 2, Bordeaux, France. yoshihide.takahashi@wanadoo.fr
Hocini
Mélèze
M
O'Neill
Mark D
MD
Sanders
Prashanthan
P
Rotter
Martin
M
Rostock
Thomas
T
Jonsson
Anders
A
Sacher
Frédéric
F
Clémenty
Jacques
J
Jaïs
Pierre
P
Haïssaguerre
Michel
M
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000628:therapy*; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation / Q000379:methods*; D004699:Endocardium; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins
D000889:Anti-Arrhythmia Agents