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473 EFFECTS OF ABLATING COMPLEX FRACTIONATED ELECTROGRAMS (CFEs) IDENTIFIED BY A NOVEL REAL-TIME AUTOMATED MAPPING ALGORITHM ON ATRIAL FIBRILLATION (AF) CYCLE LENGTH, TERMINATION, AND INDUCIBILITY A Verma, L Macle, P Novak, B Whaley, M Beardsall, Z Wulffhart, Y Khaykin Complex fractionated electrograms (CFEs) during atrial fibrillation (AF) are continuous electrograms (EGMs) of very short cycle length (CL) representing substrate for AF perpetuation. Ablation of CFEs results in AF slowing, termination, noninducibility, & prevention of recurrence. However, visual identification of CFEs is subjective and challenging.
Newmarket, Ontario
OBJECTIVE: To assess prospectively whether a novel automated algorithm can identify CFE regions and the impact of targeting these regions for ablation on AFCL, termination, and inducibility.
METHODS: 12 patients (9 male, 58±9 yrs, LA 43±4 mm, EF 53±4%) with paroxysmal (n=8) or persistent (n=4) AF were studied. A decapolar lasso catheter (2 mm spacing) and an 8 mm tip catheter were used for mapping and ablation (2 transseptal punctures). An anatomic shell of the LA and pulmonary veins (PVs) was created (EnSite NavX™). If not already in AF, AF was induced by burst pacing (+/- isoproterenol) from the coronary sinus (CS). Atrial EGMs during AF were mapped and analyzed using an automated CFE algorithm (EnSite NavX™). The algorithm measures the time between discrete deflections in a local EGM over 1 sec. Deflection detection is based on user selectable width & peak-to-peak (>0.03 mV) criteria. The mean CL of the local EGM is projected onto the LA shell as a numeric and color-coded display. All regions demonstrating CL <120 ms were labeled CFE (based on published criteria) and targeted for ablation/elimination. AFCL and regularity were measured from a CS catheter.
RESULTS: AF was spontaneous (n=5) or induced (n=7) in all patients. CFE were most commonly found along the septum (n=11), PV antra (n=9), roof (n=6), and base of the appendage (n=5). Ablation of CFE sites resulted in prolonged AFCL (194±27 ms to 316±41ms) and AF regularization in all 12 patients. AF termination during ablation occurred after AFCL prolongation in 9/12 (75%) patients. In the remaining 3 patients, AF converted to a left atrial flutter (n=2, cardioverted) or a right atrial flutter (n=1, ablated). Ablation did not cause PV isolation in most patients (mean 0.3±0.4 PV isolated/pt). Post-ablation, AF could not be induced in any patient. Four patients had inducible left atrial flutter.
CONCLUSIONS: Ablation of CFE identified by an automated algorithm resulted in AFCL prolongation, AF regularization, and AF noninducibility in all patients. There was also a high incidence of AF termination during ablation. Long-term followup is required.
DNC