Impact of nonischemic scar features on local ventricular electrograms and scar-related ventricular tachycardia circuits in patients with nonischemic cardiomyopathy.
BACKGROUND
The association of local electrogram features with scar morphology and distribution in nonischemic cardiomyopathy has not been investigated. We aimed to quantify the association of scar on late gadolinium-enhanced cardiac magnetic resonance with local electrograms and ventricular tachycardia circuit sites in patients with nonischemic cardiomyopathy.


RESULTS
Fifteen patients with nonischemic cardiomyopathy underwent late gadolinium-enhanced cardiac magnetic resonance before ventricular tachycardia ablation. The transmural extent and intramural types (endocardial, midwall, epicardial, patchy, transmural) of scar were measured in late gadolinium-enhanced cardiac magnetic resonance short-axis planes. Electroanatomic map points were registered to late gadolinium-enhanced cardiac magnetic resonance images. Myocardial wall thickness, scar transmurality, and intramural scar types were independently associated with electrogram amplitude, duration, and deflections in linear mixed-effects multivariable models, clustered by patient. Fractionated and isolated potentials were more likely to be observed in regions with higher scar transmurality (P<0.0001 by ANOVA) and in regions with patchy scar (versus endocardial, midwall, epicardial scar; P<0.05 by ANOVA). Most ventricular tachycardia circuit sites were located in scar with >25% scar transmurality.


CONCLUSIONS
Electrogram features are associated with scar morphology and distribution in patients with nonischemic cardiomyopathy. Previous knowledge of electrogram image associations may optimize procedural strategies including the decision to obtain epicardial access.
Departments of Cardiology, Biostatistics, and Radiology, Johns Hopkins University, Baltimore, MD; and Division of Radiology and Imaging Sciences, NIH Clinical Center, National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD.
Takeshi
T
Sasaki
Christopher F
CF
Miller
Rozann
R
Hansford
Vadim
V
Zipunnikov
Menekhem M
MM
Zviman
Joseph E
JE
Marine
David
D
Spragg
Alan
A
Cheng
Harikrishna
H
Tandri
Sunil
S
Sinha
Aravindan
A
Kolandaivelu
Stefan L
SL
Zimmerman
David A
DA
Bluemke
Gordon F
GF
Tomaselli
Ronald D
RD
Berger
Henry R
HR
Halperin
Hugh
H
Calkins
Saman
S
Nazarian
D000328:Adult; D009202:Cardiomyopathies / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*
tachycardia, ventricular