Dominant frequency of atrial fibrillation correlates poorly with atrial fibrillation cycle length.
BACKGROUND
Localized sites of high frequency during atrial fibrillation (AF) are used as target sites to eliminate AF. Spectral analysis is used experimentally to determine these sites. The purpose of this study was to compare dominant frequencies (DF) with AF cycle length (AFCL) of unipolar and bipolar recordings.


RESULTS
Left and right atrial endocardial electrograms were recorded during AF in 40 patients with lone AF, using two 20-polar catheters. Mean age was 53+/-9.9 years. Unipolar and bipolar electrograms were recorded simultaneously during 16 seconds at 2 right and 4 left atrial sites. AFCLs and DFs were determined. QRS subtraction was performed in unipolar signals. DFs were compared with mean, median, and mode of AFCLs; 4800 unipolar and 2400 bipolar electrograms were analyzed. Intraclass correlation was poor for all spectral analysis protocols. Best correlation was accomplished with DFs from unipolar electrograms compared with median AFCL (intraclass correlation coefficient, 0.67). A gradient in median AFCL of >25% was detected in 16 of 40 patients. In 13 of 16 patients (81%) with a frequency gradient of >25%, the site with highest frequency was located in the left atrium (posterior left atrium in 8 patients). The site with shortest median AFCL and highest DF corresponded in 25% if unipolar and in 31% if bipolar electrograms were analyzed.


CONCLUSIONS
DFs from unipolar and bipolar electrograms recorded during AF correlated poorly with mean, median, and mode AFCL. If a frequency gradient >25% existed, the site with highest DF corresponded to the site of shortest median AFCL in only 25% of patients. Because spectral analysis is being used to identify ablation sites, these data may have important clinical implications.
Department of Cardiology, Isala Klinieken, Zwolle, The Netherlands. v.r.c.derks@isala.nl
Arif
A
Elvan
Andre C
AC
Linnenbank
Marnix W
MW
van Bemmel
Anand R Ramdat
AR
Misier
Peter Paul H M
PP
Delnoy
Willem P
WP
Beukema
Jacques M T
JM
de Bakker
D000328:Adult; D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology; D003198:Computer Simulation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005583:Fourier Analysis; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors