Clinical Research
Heart Rhythm Disorder
Sites of Focal Atrial Activity Characterized by Endocardial Mapping During Atrial Fibrillation

https://doi.org/10.1016/j.jacc.2005.12.068Get rights and content
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Objectives

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 ≥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.

Abbreviations and Acronyms

AF
atrial fibrillation
LA
left atrium
PV
pulmonary vein
RA
right atrium
RF
radiofrequency
SVC
superior vena cava

Cited by (0)

1

Dr. O’Neill is supported by a British Heart Foundation International Fellowship.

2

Dr. Sanders is supported by the Neil Hamilton Fairley Fellowship from the National Health and Medical Research Council of Australia and the Ralph Reader Fellowship from the National Heart Foundation of Australia.

3

Dr. Rotter is supported by the Swiss National Foundation for Scientific Research, Bern, Switzerland.

4

Dr. Rostock is supported by the German Cardiac Society.

5

Dr. Jonsson is supported by the Swedish Society of Cardiology. PentaRay catheters were developed and provided free of charge for the study by Biosense Webster.

6

Drs. Sanders, Jaïs, and Haïssaguerre report having served on the advisory board of and having received lecture fees from Biosense Webster.

7

Dr. Rotter reports having received lecture fees from Biosense Webster.