Atrial tachycardias utilizing the Ligament of Marshall region following single ring pulmonary vein isolation for atrial fibrillation.
BACKGROUND
Organized atrial tachycardias (OATs) after pulmonary vein isolation (PVI) procedure are common. Arrhythmia mechanisms include mitral annular, ring gap, or roof-dependent gap-related flutters. In this series, we describe a mechanism of arrhythmia utilizing the ridge between left pulmonary vein (PV) and left atrial appendage (LAA) in the Ligament of Marshall (LOM) region.


RESULTS
Five tachycardias involving the LOM region were identified from a group of 240 patients who underwent a single ring PVI procedure for symptomatic atrial fibrillation. The common characteristics of these tachycardias were the endocardial breakout over a broad area adjacent to the LOM region, presence of presystolic or mid-diastolic potentials, and abolition by ablation of the presystolic or mid-diastolic potentials remote from the endocardial breakout site. In all five cases, tachycardias were present after isolation of the veins and posterior left atria. All demonstrated characteristic areas of very slow conduction in the LOM region highlighted by presence of either low voltage, long duration fractionated potentials, or mid-diastolic potentials with a fixed temporal relationship to the subsequent endocardial activation. The pattern of activation and termination of tachycardia during ablation was consistent with an arrhythmia utilizing an electrically insulated tract within LOM and the PV-LAA ridge region.


CONCLUSIONS
We identified a pattern of arrhythmias involving a concealed presystolic component and a broad endocardial breakout site related to the LOM region. Successful ablation site involved careful identification of small diastolic potentials in the LAA/ridge region or adjacent to the coronary sinus.
Cardiology Department, Westmead Public and Private Hospitals, Sydney, Australia; Sydney Medical School, University of Sydney, Sydney, Australia.
William W B
WW
Chik
Jacky Kit
JK
Chan
David L
DL
Ross
Jackie
J
Wagstaff
Eddy
E
Kizana
Aravinda
A
Thiagalingam
Pramesh
P
Kovoor
Stuart P
SP
Thomas
D000368:Aged; D001281:Atrial Fibrillation / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D006801:Humans; D008022:Ligaments / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery*; D012008:Recurrence; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000503:physiopathology*; D016896:Treatment Outcome
ablation; arrhythmia; atrial fibrillation; atrial tachycardia; catheter ablation; electrophysiology; ligament of Marshall