Electrophysiologic and electrocardiographic characteristics and radiofrequency catheter ablation of focal atrial tachycardia originating from the left atrial appendage.
BACKGROUND
The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs).


OBJECTIVE
The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA.


METHODS
The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA.


RESULTS
The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years.


CONCLUSIONS
LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation.
Yamada
Takumi
T
Cardiac Rhythm Management Laboratory, Division of Cardiovascular Diseases, University of Alabama at Birmingham, 1670 University Boulevard, 1530 Third Avenue S., Birmingham, AL 35294, USA. takumi-y@fb4.so-net.ne.jp
Murakami
Yoshimasa
Y
Yoshida
Yukihiko
Y
Okada
Taro
T
Yoshida
Naoki
N
Toyama
Junji
J
Tsuboi
Naoya
N
Inden
Yasuya
Y
Hirai
Makoto
M
Murohara
Toyoaki
T
McElderry
Hugh T
HT
Epstein
Andrew E
AE
Plumb
Vance J
VJ
Kay
G Neal
GN
D000328:Adult; D020517:Atrial Appendage / Q000503:physiopathology* / Q000601:surgery; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted