The Different Substrate Characteristics of Arrhythmogenic Triggers in Idiopathic Right Ventricular Outflow Tract Tachycardia and Arrhythmogenic Right Ventricular Dysplasia: New Insight from Noncontact Mapping.
BACKGROUND
The aim of this study was to investigate the different substrate characteristics of repetitive premature ventricular complexed (PVC) trigger sites by the non-contact mapping (NCM).


METHODS
Thirty-five consecutive patients, including 14 with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) and 21 with idiopathic right ventricular outflow tract tachycardia (RVOT VT), were enrolled for electrophysiological study and catheter ablation guided by the NCM. Substrate and electrogram (Eg) characteristics of the earliest activation (EA) and breakout (BO) sites of PVCs were investigated, and these were confirmed by successful PVC elimination.


RESULTS
Overall 35 dominant focal PVCs were identified. PVCs arose from the focal origins with preferential conduction, breakout, and spread to the whole right ventricle. The conduction time and distance from EA to BO site were both longer in the ARVC than the RVOT group. The conduction velocity was similar between the 2 groups. The negative deflection of local unipolar Eg at the EA site (EA slope3,5,10ms values) was steeper in the RVOT, compared to ARVC patients. The PVCs of ARVC occurred in the diseased substrate in the ARVC patients. More radiofrequency applications were required to eliminate the triggers in ARVC patients.


CONCLUSIONS
The substrate characteristics of PVC trigger may help to differentiate between idiopathic RVOT VT and ARVC. The slowing and slurred QS unipolar electrograms and longer distance from EA to BO in RVOT endocardium suggest that the triggers of ARVC may originate from mid- or sub-epicardial myocardium. More extensive ablation to the trigger site was required in order to create deeper lesions for a successful outcome.
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Van Buu Dan
VB
Do
Division of Cardiology, Department of Medicine, Hualien Tzu-Chi General Hospital, Taipei, Taiwan.
Wen-Chin
WC
Tsai
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
Yenn-Jiang
YJ
Lin
Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Okinawa, Japan.
Satoshi
S
Higa
Division of Cardiovascular Medicine, Nakagami Hospital, Okinawa, Japan.
Nobumori
N
Yagi
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
Shih-Lin
SL
Chang
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
Li-Wei
LW
Lo
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Fa-Po
FP
Chung
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Jo-Nan
JN
Liao
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Yen-Chang
YC
Huang
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Chao-Shun
CS
Chan
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Hung-Kai
HK
Huang
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
Yu-Feng
YF
Hu
Cardiology, National Yang Ming University Hospital, I-Lan, Taiwan.
Hsuan-Ming
HM
Tsao
Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
Shih-Ann
SA
Chen
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D004699:Endocardium / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome