title: Late Gadolinium Enhancement on Cardiac MRI Correlates with QT Dynamicity Represented by QT/RR Relationship in Patients with Ventricular Arrhythmias.
abstract: BACKGROUND
  The distribution of late gadolinium enhancement (LGE) on the cardiac MRI (CMR) indicates myocardial fibrosis and provides information of possible reentry substrates. QT dynamicity reflecting repolarization abnormalities has gained attention as a potential prognostic predictive factor.
  
  
  OBJECTIVE
  To clarify the correlation between the LGE distribution on CMR and QT dynamicity represented by the QT/RR relationship.
  
  
  METHODS
  CMR and QT/RR analyses using Holter monitoring were performed in 34 patients (24 males, 60 ± 11 years) with ventricular tachycardia (VT) and/or ventricular fibrillation (VF). The LGE on CMR was scored using a 4-point score in 17 left ventricular segments. The sum of the LGE scores was calculated for each patient. The QT/RR slope and daytime/nighttime QT/RR ratio (day/night ratio) were calculated. The correlation between the slope or the day/night QT/RR ratio and late enhancement findings was analyzed.
  
  
  RESULTS
  All patients were divided into 23 LGE positive (LGE(+)) and 11 LGE negative (LGE(-)) patients. The slopes of the QTe/RR and QTa /RR were significantly steeper in the LGE(+) than in LGE(-) patients (0.21 ± 0.03 vs 0.13 ± 0.02; P < 0.001, 0.19 ± 0.03 vs 0.13 ± 0.02; P < 0.001, respectively), and both slopes were significantly correlated with the total LGE scores (r = 0.83, P < 0.001; r = 0.71, P < 0.001, respectively). In the LGE(+) patients, the QTe day/night (1.37 ± 0.38 vs 0.91 ± 0.33; P = 0.002) and QTa day/night ratios (1.33 ± 0.26 vs 1.06 ± 0.30; P = 0.011) were significantly greater than those in the LGE(-) patients.
  
  
  CONCLUSIONS
  The LGE distribution was closely related to the QT dynamicity, suggesting that a combination of these markers can be a powerful tool for understanding the background pathophysiology.
authors.affiliation: Department of Cardiology.
authors.forename: Naka
authors.initials: N
authors.lastname: Sakamoto
authors.affiliation: Department of Cardiology.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Department of Cardiology.
authors.forename: Ahmed Karim
authors.initials: AK
authors.lastname: Talib
authors.affiliation: Department of Cardiology.
authors.forename: Eitaro
authors.initials: E
authors.lastname: Sugiyama
authors.affiliation: Department of Cardiology.
authors.forename: Akiho
authors.initials: A
authors.lastname: Minoshima
authors.affiliation: Department of Cardiology.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tanabe
authors.affiliation: Department of Cardiology.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fujino
authors.affiliation: Department of Cardiology.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Takeuchi
authors.affiliation: Department of Cardiology.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Akasaka
authors.affiliation: Division of Community Medicine and Epidemiology Department of Health Science, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Saijo
authors.affiliation: Department of Cardiology.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: Department of Cardiology.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hasebe
mesh_terms: D003287:Contrast Media; D015716:Electrocardiography, Ambulatory; D005682:Gadolinium; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014693:Ventricular Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: QT dynamicity; cardiac MRI; late gadolinium enhancement; sudden cardiac death; ventricular fibrillation; ventricular tachycardia