High-density substrate-guided ventricular tachycardia ablation: role of activation mapping in an attempt to improve procedural effectiveness.
BACKGROUND
Advanced techniques of electroanatomical mapping efficiently guide ventricular tachycardia (VT) ablation strategies; in this context, the adjunctive value of combining activation mapping (AMap) to improve accuracy has not been elucidated.


OBJECTIVE
To investigate whether conventional AMap further contributes to the identification of critical sites of VT reentry and whether this translates into a more effective ablation outcome in a cohort of patients undergoing VT ablation.


METHODS
We prospectively enrolled 126 patients (mean age 65.3 ± 10.5 years; left ventricular ejection fraction 33.3% ± 7.2%) with ischemic (n = 89) or idiopathic (n = 37) dilated cardiomyopathy undergoing endocardial (n = 105) or endo-epicardial (n = 21) electroanatomical mapping and ablation. A substrate-guided strategy targeting surrogate markers of reentry was accomplished in all patients, but the feasibility and efficacy of AMap was preliminarily assessed for all induced VTs focusing on early VT suppression obtained during radiofrequency delivery. VT-free survival was assessed by ICD interrogation.


RESULTS
AMap successfully guided ablation in 62 of 104 (59.6%) patients with inducible VT(s). At 1 year, 6 of 126 (4.8%) patients died; VT recurred in 28 of 126 (22.2%) patients. No significant difference in VT recurrence rate was observed between patients in whom AMap proved effective versus those in whom substrate-guided ablation was not corroborated by AMap (16 of 62 [25.8%] vs 12 of 64 [18.8%]; log-rank test, P = .3).


CONCLUSIONS
Our findings support the efficacy of a substrate-guided strategy targeting specific markers of arrhythmogenicity identified during sinus rhythm. AMap proves highly efficient acutely but does not improve overall VT-free survival, suggesting that in patients with advanced cardiac disease, life-threatening arrhythmias can be successfully treated by ablation in sinus rhythm, thus limiting procedural risks.
Cardiac Arrhythmia Research Centre, Centro Cardiologico Monzino, IRCCS, Milan, Italy. Electronic address: corrado.carbucicchio@ccfm.it.
Corrado
C
Carbucicchio
Nadeem
N
Ahmad Raja
Luigi
L
Di Biase
Valeria
V
Volpe
Antonio
A
Dello Russo
Chintan
C
Trivedi
Stefano
S
Bartoletti
Martina
M
Zucchetti
Michela
M
Casella
Eleonora
E
Russo
Pasquale
P
Santangeli
Massimo
M
Moltrasio
Fabrizio
F
Tundo
Gaetano
G
Fassini
Andrea
A
Natale
Claudio
C
Tondo
D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
AMap; Catheter ablation; EAM; EGM; EP; Electroanatomical mapping; ICD; ICM; IDCM; Ischemic heart disease; LV; Nonischemic cardiomyopathy; PES; RF; RV; VT; Ventricular tachycardia; activation mapping; electroanatomical mapping; electrogram; electrophysiology; idiopathic dilated cardiomyopathy; implantable cardioverter-defibrillator; ischemic cardiomyopathy; left ventricle/ventricular; programmed electrical stimulation; radiofrequency; right ventricular; ventricular tachycardia