title: Myocardial fibrosis evaluated by Look-Locker and late gadolinium enhancement magnetic resonance imaging in apical hypertrophic cardiomyopathy: association with ventricular tachyarrhythmia and risk factors.
abstract: OBJECTIVE
  To evaluate the distribution and extent of myocardial fibrosis identified by either contrast-enhanced Look-Locker or late gadolinium enhancement magnetic resonance imaging (LGE MRI) and their relationships between ventricular tachyarrhythmia or risk factors in apical hypertrophic cardiomyopathy (APH).
  
  
  METHODS
  Twenty-five APH patients were examined using a 3.0 T or 1.5 T instrument. We used MRI to evaluate myocardial T1 values and scar. We compared the myocardial fibrosis assessed by contrast-enhanced Look-Locker or LGE MRI with ventricular tachyarrhythmia or risk factors for hypertrophic cardiomyopathy.
  
  
  RESULTS
  Myocardial scar was present in 17 of the 25 patients with APH. Myocardial scar was distributed predominantly in the apical myocardium (P < 0.01), whereas myocardial T1 values did not differ between the apical, midventricular, and basal septum. The extent of myocardial scar according to 16-segment model and ejection fraction were related to ventricular tachyarrhythmia or risk factors in APH (P < 0.05 for both). The myocardial T1 value was not associated with the tachyarrhythmia or risk factors.
  
  
  CONCLUSIONS
  In APH, the extent of myocardial scar on LGE MRI is associated with ventricular tachyarrhythmia and risk factors. Quantification of the myocardial T1 value is not necessary for its risk stratification.
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Amano
authors.forename: Minako
authors.initials: M
authors.lastname: Takeda
authors.forename: Masaki
authors.initials: M
authors.lastname: Tachi
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Kitamura
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kumita
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005355:Fibrosis / Q000150:complications / Q000473:pathology; D005682:Gadolinium / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000473:pathology*
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: apical hypertrophic cardiomyopathy; arrhythmia; magnetic resonance imaging; myocardial fibrosis; risk factor