Classifying fractionated electrograms in human atrial fibrillation using monophasic action potentials and activation mapping: evidence for localized drivers, rate acceleration, and nonlocal signal etiologies.
BACKGROUND
Complex fractionated electrograms (CFAEs) detected during substrate mapping for atrial fibrillation (AF) reflect etiologies that are difficult to separate. Without knowledge of local refractoriness and activation sequence, CFAEs may represent rapid localized activity, disorganized wave collisions, or far-field electrograms.


OBJECTIVE
The purpose of this study was to separate CFAE types in human AF, using monophasic action potentials (MAPs) to map local refractoriness in AF and multipolar catheters to map activation sequence.


METHODS
MAP and adjacent activation sequences at 124 biatrial sites were studied in 18 patients prior to AF ablation (age 57 ± 13 years, left atrial diameter 45 ± 8 mm). AF cycle length, bipolar voltage, and spectral dominant frequency were measured to characterize types of CFAE.


RESULTS
CFAE were observed at 91 sites, most of which showed discrete MAPs and (1) pansystolic local activity (8%); (2) CFAE after AF acceleration, often with MAP alternans (8%); or (3) nonlocal (far-field) signals (67%). A fourth CFAE pattern lacked discrete MAPs (17%), consistent with spatial disorganization. CFAE with discrete MAPs and pansystolic activation (consistent with rapid localized AF sites) had shorter cycle length (P <.05) and lower voltage (P <.05) and trended to have higher dominant frequency than other CFAE sites. Many CFAEs, particularly at the septa and coronary sinus, represented far-field signals.


CONCLUSIONS
CFAEs in human AF represent distinct functional types that may be separated using MAPs and activation sequence. In a minority of cases, CFAEs indicate localized rapid AF sites. The majority of CFAEs reflect far-field signals, AF acceleration, or disorganization. These results may help to interpret CFAE during AF substrate mapping.
University of California and Veterans Affairs Medical Center, San Diego, California 92161, USA. snarayan@ucsd.edu
Sanjiv M
SM
Narayan
Matthew
M
Wright
Nicolas
N
Derval
Amir
A
Jadidi
Andrei
A
Forclaz
Isabelle
I
Nault
Shinsuke
S
Miyazaki
Frédéric
F
Sacher
Pierre
P
Bordachar
Jacques
J
Clémenty
Pierre
P
Jaïs
Michel
M
Haïssaguerre
Mélèze
M
Hocini
D000200:Action Potentials / Q000502:physiology*; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000145:classification* / Q000379:methods; D017115:Catheter Ablation / Q000379:methods; D015331:Cohort Studies; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D004562:Electrocardiography / Q000145:classification / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods; D018570:Risk Assessment; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D016896:Treatment Outcome