Focal atrial tachycardia: new insight from noncontact mapping and catheter ablation.
BACKGROUND
This study investigated the electrophysiologic characteristics, atrial activation pattern, and effects of radiofrequency (RF) catheter ablation guided by noncontact mapping system in patients with focal atrial tachycardia (AT).


RESULTS
In 13 patients with 14 focal ATs, noncontact mapping system was used to map and guide ablation of AT. AT origins were in the crista terminalis (n=8), right atrial (RA) free wall (n=3), Koch triangle (n=1), anterior portion of RA-inferior vena cava junction (n=1), and superior portion of tricuspid annulus (n=1); breakout sites were in the crista terminalis (n=5), RA free wall (n=5), middle cavotricuspid isthmus (n=2), and RA-superior vena cava junction (n=2). ATs arose from the focal origins (11 ATs inside or at the border of low-voltage zone), with preferential conduction, breakout, and spread to the whole atrium. After applications of RF energy on the earliest activation site or the proximal portion of preferential conduction from AT origin, 13 ATs were eliminated without complication. During the follow-up period (8+/-5 months), 11 (91.7%) of the 12 patients with successful ablation were free of focal ATs.


CONCLUSIONS
Focal AT originates from a small area and spreads out to the whole atrium through a preferential conduction. Application of RF energy guided by noncontact mapping system was effective and safe in eliminating focal AT.
Higa
Satoshi
S
Division of Cardiology, Department of Medicine, National Yang-Ming, University School of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Tai
Ching-Tai
CT
Lin
Yenn-Jiang
YJ
Liu
Tu-Ying
TY
Lee
Pi-Chang
PC
Huang
Jin-Long
JL
Hsieh
Ming-Hsiung
MH
Yuniadi
Yoga
Y
Huang
Bien-Hsien
BH
Lee
Shih-Huang
SH
Ueng
Kwo-Chang
KC
Ding
Yu-An
YA
Chen
Shih-Ann
SA
D000241:Adenosine / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery*
D000889:Anti-Arrhythmia Agents; D000241:Adenosine