Catheter ablation of ventricular arrhythmia in nonischemic cardiomyopathy: anteroseptal versus inferolateral scar sub-types.
BACKGROUND
The aim was to relate distinct scar distributions found in nonischemic cardiomyopathy with ventricular tachycardia (VT) morphology, late potential distribution, ablation strategy, and outcome.


RESULTS
Eighty-seven patients underwent catheter ablation for drug-refractory VT. Based on endocardial unipolar voltage, 44 were classified as predominantly anteroseptal and 43 as inferolateral. Anteroseptal patients more frequently fulfilled diagnostic criteria for dilated cardiomyopathy (64% versus 36%), associated with more extensive endocardial unipolar scar (41 [22-83] versus 9 [1-29] cm(2); P<0.001). Left inferior VT axis was predictive of anteroseptal scar (positive predictive value, 100%) and right superior axis for inferolateral (positive predictive value, 89%). Late potentials were infrequent in the anteroseptal group (11% versus 74%; P<0.001). Epicardial late potentials were common in the inferolateral group (81% versus 4%; P<0.001) and correlated with VT termination sites (κ=0.667; P=0.014), whereas no anteroseptal patient had an epicardial VT termination (P<0.001). VT recurred in 44 patients (51%) during a median follow-up of 1.5 years. Anteroseptal scar was associated with higher VT recurrence (74% versus 25%; log-rank P<0.001) and redo procedure rates (59% versus 7%; log-rank P<0.001). After multivariable analysis, clinical predictors of VT recurrence were electrical storm (hazard ratio, 3.211; P=0.001) and New York Heart Association class (hazard ratio, 1.608; P=0.018); the only procedural predictor of VT recurrence was anteroseptal scar pattern (hazard ratio, 5.547; P<0.001).


CONCLUSIONS
Unipolar low-voltage distribution in nonischemic cardiomyopathy allows categorization of scar pattern as inferolateral, often requiring epicardial ablation mainly based on late potentials, and anteroseptal, which frequently involves an intramural septal substrate, leading to a higher VT recurrence.
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Teresa
T
Oloriz
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
John
J
Silberbauer
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Giuseppe
G
Maccabelli
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Hiroya
H
Mizuno
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Francesca
F
Baratto
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Senthil
S
Kirubakaran
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Pasquale
P
Vergara
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Caterina
C
Bisceglia
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Giulia
G
Santagostino
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Alessandra
A
Marzi
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Nicoleta
N
Sora
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Carla
C
Roque
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Fabrizio
F
Guarracini
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Dimitris
D
Tsiachris
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Andrea
A
Radinovic
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Manuela
M
Cireddu
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Simone
S
Sala
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Simone
S
Gulletta
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Gabriele
G
Paglino
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Patrizio
P
Mazzone
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.
Nicola
N
Trevisi
From the Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy. dellabella.paolo@hsr.it.
Paolo
P
Della Bella
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D009202:Cardiomyopathies / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology; D015331:Cohort Studies; D004562:Electrocardiography / Q000379:methods*; D056149:Epicardial Mapping / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006346:Heart Septum / Q000473:pathology; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D016896:Treatment Outcome
cardiomyopathies; tachycardia, ventricular