Ablation of atypical atrial flutters using ultra high density-activation sequence mapping.
OBJECTIVE
The purpose of this study was to evaluate ultra high density-activation sequence mapping (UHD-ASM) for ablating atypical atrial flutters.


METHODS
For 23 patients with 31 atypical atrial flutters (AAF), we created UHD-ASM.


RESULTS
Demographics age = 65.3 ± 8.5 years, male = 78%, left atrial size = 4.66 ± 0.64 cm, redo ablation 20/23(87%). AAF were left atrial in 30 (97%). For each AAF, 1273 ± 697 points were used for UHD-ASM. Time to create and interpret the UHD-ASM was 20 ± 11 min. For every AAF, the entire circuit was identified. Thirty (97%) were macroreentry. AAF cycle length was 267 ± 49 ms, and the circuit length was 138 ± 38 mm (range 35-187). Macroreentry atrial flutters took varied pathways, but each had an area of slow conduction (ASC) averaging 16 ± 6 mm (range 6-29) in length. Entrainment was not utilized. We targeted the ASC and ablation terminated AAF directly in 19/31 (61.3%) and altered AAF activation in 7/31 (22.6%), all of which terminated directly with additional mapping/ablation. AAF degenerated to atrial fibrillation in 2/31 (6.5%) with RF and could not be reinduced after ASC ablation. Median time from initial ablation to AAF termination was 64 s. Thus, 28/31 (90.3%) terminated with RF energy and/or could not be reinduced after ASC ablation. At 1 year of follow-up, 77% were free of atrial tachycardia or atrial flutter and 61% were free of all atrial arrhythmias.


CONCLUSIONS
Using rapidly acquired UHD-ASM, the entire AAF circuit as well as the target ASC could be identified. Most AAF were left atrial macroreentry. Ablation of the ASC or microreentry focuses directly terminated or eliminated AAF in 90.3% without the need for entrainment mapping.
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA. rawinkle@aol.com.|Sequoia Hospital, Redwood City, CA, USA. rawinkle@aol.com.
Roger A
RA
Winkle
St. Jude Medical, Inc., St. Paul, MD, USA.
Ryan
R
Moskovitz
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA.|Sequoia Hospital, Redwood City, CA, USA.
R Hardwin
RH
Mead
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA.|Sequoia Hospital, Redwood City, CA, USA.
Gregory
G
Engel
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA.|Sequoia Hospital, Redwood City, CA, USA.
Melissa H
MH
Kong
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA.|Sequoia Hospital, Redwood City, CA, USA.
William
W
Fleming
Silicon Valley Cardiology, 1950 University Avenue, Suite 160, E. Palo Alto, CA, 94303, USA.|Sequoia Hospital, Redwood City, CA, USA.
Rob A
RA
Patrawala
D000368:Aged; D001282:Atrial Flutter / Q000175:diagnosis* / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
Activation mapping; Atrial flutter; Atrial flutter ablation; Atypical atrial flutter; Left atrial flutter