TY - JOUR
T1 - Characterization of the Arrhythmogenic Substrate in Ischemic and Nonischemic Cardiomyopathy. Implications for Catheter Ablation of Hemodynamically Unstable Ventricular Tachycardia
AU - Nakahara, Shiro
AU - Tung, Roderick
AU - Ramirez, Rafael J.
AU - Michowitz, Yoav
AU - Vaseghi, Marmar
AU - Buch, Eric
AU - Gima, Jean
AU - Wiener, Isaac
AU - Mahajan, Aman
AU - Boyle, Noel G.
AU - Shivkumar, Kalyanam
N1 - Funding Information:
Supported by the National Heart, Lung, and Blood Institute ( R01-HL084261 and R01-HL067647 to Dr. Shivkumar). Dr. Shivkumar's institution has received support from St. Jude Medical and Biosense Webster ; this support is unrelated to the current study. Drs. Nakahara and Tung contributed equally to this work.
PY - 2010/5/25
Y1 - 2010/5/25
N2 - Objectives: The purpose of this study was to compare the characteristics and prevalence of late potentials (LP) in patients with nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) etiologies and evaluate their value as targets for catheter ablation. Background: LP are frequently found in post-myocardial infarction scars and are useful ablation targets. The relative prevalence and characteristics of LP in patients with NICM is not well understood. Methods: Thirty-three patients with structural heart disease (NICM, n = 16; ICM, n = 17) referred for catheter ablation of ventricular tachycardia were studied. Electroanatomic mapping was performed endocardially (n = 33) and epicardially (n = 19). The LP were defined as low voltage electrograms (<1.5 mV) with onset after the QRS interval. Very late potentials (vLP) were defined as electrograms with onset >100 ms after the QRS. Results: We sampled an average of 564 ± 449 points and 726 ± 483 points in the left ventricle endocardium and epicardium, respectively. Mean total low voltage area in patients with ICM was 101 ± 55 cm2 and 56 ± 33 cm2, endocardial and epicardial, respectively, compared with NICM of 55 ± 41 cm2 and 53 ± 28 cm2, respectively. Within the total low voltage area, vLP were observed more frequently in ICM than in NICM in endocardium (4.1% vs. 1.3%; p = 0.0003) and epicardium (4.3% vs. 2.1%, p = 0.035). An LP-targeted ablation strategy was effective in ICM patients (82% nonrecurrence at 12 ± 10 months of follow-up), whereas NICM patients had less favorable outcomes (50% at 15 ± 13 months of follow-up). Conclusions: The contribution of scar to the electrophysiological abnormalities targeted for ablation of unstable ventricular tachycardia differs between ICM and NICM. An approach incorporating LP ablation and pace-mapping had limited success in patients with NICM compared with ICM, and alternative ablation strategies should be considered.
AB - Objectives: The purpose of this study was to compare the characteristics and prevalence of late potentials (LP) in patients with nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) etiologies and evaluate their value as targets for catheter ablation. Background: LP are frequently found in post-myocardial infarction scars and are useful ablation targets. The relative prevalence and characteristics of LP in patients with NICM is not well understood. Methods: Thirty-three patients with structural heart disease (NICM, n = 16; ICM, n = 17) referred for catheter ablation of ventricular tachycardia were studied. Electroanatomic mapping was performed endocardially (n = 33) and epicardially (n = 19). The LP were defined as low voltage electrograms (<1.5 mV) with onset after the QRS interval. Very late potentials (vLP) were defined as electrograms with onset >100 ms after the QRS. Results: We sampled an average of 564 ± 449 points and 726 ± 483 points in the left ventricle endocardium and epicardium, respectively. Mean total low voltage area in patients with ICM was 101 ± 55 cm2 and 56 ± 33 cm2, endocardial and epicardial, respectively, compared with NICM of 55 ± 41 cm2 and 53 ± 28 cm2, respectively. Within the total low voltage area, vLP were observed more frequently in ICM than in NICM in endocardium (4.1% vs. 1.3%; p = 0.0003) and epicardium (4.3% vs. 2.1%, p = 0.035). An LP-targeted ablation strategy was effective in ICM patients (82% nonrecurrence at 12 ± 10 months of follow-up), whereas NICM patients had less favorable outcomes (50% at 15 ± 13 months of follow-up). Conclusions: The contribution of scar to the electrophysiological abnormalities targeted for ablation of unstable ventricular tachycardia differs between ICM and NICM. An approach incorporating LP ablation and pace-mapping had limited success in patients with NICM compared with ICM, and alternative ablation strategies should be considered.
KW - catheter ablation
KW - late potentials
KW - myocardial infarct scars
KW - ventricular tachycardia
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U2 - 10.1016/j.jacc.2010.01.041
DO - 10.1016/j.jacc.2010.01.041
M3 - Article
C2 - 20488307
AN - SCOPUS:77952160809
SN - 0735-1097
VL - 55
SP - 2355
EP - 2365
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
IS - 21
ER -