title: Late gadolinium enhancement on cardiac magnetic resonance represents the depolarizing and repolarizing electrically damaged foci causing malignant ventricular arrhythmia in hypertrophic cardiomyopathy.
abstract: BACKGROUND
  The presence of a myocardial scar detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) has been described as a predictor of all-cause mortality in hypertrophic cardiomyopathy (HCM). However, the detailed spatial relationship between LGE site and electrical abnormality is unclear in high-risk HCM with malignant arrhythmia.
  
  
  OBJECTIVE
  The purpose of this study was to elucidate the detailed relationship between the site on CMR imaging and the electrically damaged site, a potential origin of ventricular arrhythmias in patients with HCM.
  
  
  METHODS
  Fifty consecutive HCM patients underwent contrast-enhanced CMR. Of those patients, 18 patients with ventricular tachycardia underwent electrophysiology study including endocardial mapping of the left ventricle (LV). The LGE area was calculated at 12 different LV sites: anterior, lateral, posterior, and septal segments of the basal, middle, and apical portions. At each LV site, the bipolar electrogram, effective refractory period (ERP), and monophasic action potential were recorded.
  
  
  RESULTS
  LGE-positive segments demonstrated a significantly lower amplitude (4.0 ± 2.8 mV vs 7.3 ± 3.6 mV; P < .001), longer duration (54.7 ± 17.8 vs 40.6 ± 7.8 ms; P < .001), longer ERP (320 ± 42 ms vs 284 ± 37 ms; P = .001), and longer monophasic action potential duration measured at 90% repolarization (321 ± 19 ms vs 283 ± 25 ms; P < .001) than did LGE-negative segments. The LGE area negatively correlated with the amplitude (r = -0.59; P < .001) and positively correlated with the duration (r = 0.64; P < .001), ERP (r = 0.44; P < .001), and action potential duration measured at 90% repolarization (r = 0.63; P < .001). All the observed VTs originated from LGE-positive segments.
  
  
  CONCLUSIONS
  The spatial distribution of LGE significantly correlates with depolarizing and repolarizing electrical damage in high-risk HCM with malignant ventricular arrhythmia.
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Naka
authors: N
authors: Sakamoto
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Yuichiro
authors: Y
authors: Kawamura
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: nsato@asahikawa-med.ac.jp.
authors: Nobuyuki
authors: N
authors: Sato
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Asami
authors: A
authors: Nimura
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Motoki
authors: M
authors: Matsuki
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Atsushi
authors: A
authors: Yamauchi
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Takayasu
authors: T
authors: Kanno
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Yasuko
authors: Y
authors: Tanabe
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Toshiharu
authors: T
authors: Takeuchi
authors: Department of Cardiology, Furano Hospital, Furano, Japan.
authors: Shunsuke
authors: S
authors: Natori
authors: Division of Community Medicine and Epidemiology, Department of Health Science.
authors: Yasuaki
authors: Y
authors: Saijo
authors: Department of Radiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Tamio
authors: T
authors: Aburano
authors: Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
authors: Naoyuki
authors: N
authors: Hasebe
mesh_terms: D001145:Arrhythmias, Cardiac / Q000209:etiology*; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications*; D005260:Female; D005682:Gadolinium / Q000494:pharmacology; D006352:Heart Ventricles; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000503:physiopathology
chemical_list: D005682:Gadolinium
keywords: Cardiac magnetic resonance; Hypertrophic cardiomyopathy; Late gadolinium enhancement; Ventricular tachycardia