Relationship between sinus rhythm late activation zones and critical sites for scar-related ventricular tachycardia: systematic analysis of isochronal late activation mapping.
BACKGROUND
It is not known whether the most delayed late potentials are functionally most specific for scar-related ventricular tachycardia (VT) circuits.


RESULTS
Isochronal late activation maps were constructed to display ventricular activation during sinus rhythm over 8 isochrones. Analysis was performed at successful VT termination sites and prospectively tested. Thirty-three patients with 47 scar-related VTs where a critical site was demonstrated by termination of VT during ablation were retrospectively analyzed. In those who underwent mapping of multiple surfaces, 90% of critical sites were on the surface that contained the latest late potential. However, only 11% of critical sites were localized to the latest isochrone (87.5%-100%) of ventricular activation. The median percentage of latest activation at critical sites was 78% at a distance from the latest isochrone of 18 mm. Sites critical to reentry were harbored in regions with slow conduction velocity, where 3 isochrones were present within a 1-cm radius. Ten consecutive patients underwent ablation prospectively guided by isochronal late activation maps, targeting concentric isochrones outside of the latest isochrone. Elimination of the targeted VT was achieved in 90%. Termination of VT was achieved in 6 patients at a mean ventricular activation percentage of 78%, with only 1 requiring ablation in the latest isochrone.


CONCLUSIONS
Late potentials identified in the latest isochrone of activation during sinus rhythm are infrequently correlated with successful ablation sites for VT. The targeting of slow conduction regions propagating into the latest zone of activation may be a novel and promising strategy for substrate modification.
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Tadanobu
T
Irie
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Ricky
R
Yu
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Jason S
JS
Bradfield
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Marmar
M
Vaseghi
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Eric F
EF
Buch
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Olujimi
O
Ajijola
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Carlos
C
Macias
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Osamu
O
Fujimura
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Ravi
R
Mandapati
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Noel G
NG
Boyle
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Kalyanam
K
Shivkumar
From the University of California at Los Angeles Cardiac Arrhythmia Center, UCLA Health System, David Geffen School of Medicine at UCLA.
Roderick
R
Tung
D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D002921:Cicatrix / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome
ablation techniques; tachycardia; ventricular