High-density mapping of atrial fibrillation in humans: relationship between high-frequency activation and electrogram fractionation.
BACKGROUND
Sites of complex fractionated atrial electrograms (CFAE) and dominant frequency (DF) have been implicated in maintaining atrial fibrillation (AF); however, their relationship is poorly understood.


RESULTS
Twenty patients underwent biatrial high-density contact mapping (507 +/- 150 points/patient) during AF. CFAE were characterized using software to quantify electrogram complexity (CFE-mean). Spectral analysis determined the frequency with greatest power and sites of high DF with a frequency gradient. CFE-mean was higher (less fractionated) for right compared with left atria (P < 0.001) and in paroxysmal compared with persistent AF (P < 0.001). DF was lower for right compared with left atria (P = 0.02) and in paroxysmal compared with persistent AF (P < 0.001). There was significant regional variation in DF in paroxysmal (P < 0.001) but not persistent AF. Highest DF points clustered together with 5.2 +/- 1.7 clusters/patient. Correlation between CFE-mean and DF was poor on a point-by-point basis (r =-0.17, P < 0.001), but moderate on an individual basis (r =-0.50, P = 0.03). Exploration of their spatial relationship demonstrated CFAE areas in close proximity (median 5 mm, IQR 2-10) to high DF sites; within 10 mm in 80% and 10-20 mm in 10%. Simultaneous activation mapping at these sites further supports this observation.


CONCLUSIONS
Greater fractionation and higher DF are seen in persistent AF and left atria during AF. Preferential areas of high DF are observed in paroxysmal but not persistent AF. CFAE and DF correlate within an individual but not point-by-point. Exploration of their spatial relationship demonstrates CFAE in areas adjacent to high DF, and this is supported by activation mapping at these sites.
Stiles
Martin K
MK
Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital, Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia.
Brooks
Anthony G
AG
Kuklik
Pawel
P
John
Bobby
B
Dimitri
Hany
H
Lau
Dennis H
DH
Wilson
Lauren
L
Dhar
Shashi
S
Roberts-Thomson
Ross L
RL
Mackenzie
Lorraine
L
Young
Glenn D
GD
Sanders
Prashanthan
P
D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged