title: Myocardial scar predicts monomorphic ventricular tachycardia but not polymorphic ventricular tachycardia or ventricular fibrillation in nonischemic dilated cardiomyopathy.
abstract: BACKGROUND
  The relation between myocardial scar and different types of ventricular arrhythmias in patients with nonischemic dilated cardiomyopathy (NIDCM) is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to analyze the effect of myocardial scar, assessed by late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), on the occurrence and type of ventricular arrhythmia in patients with NIDCM.
  
  
  METHODS
  Consecutive patients with NIDCM who underwent LGE-CMR and implantable cardioverter-defibrillator (ICD) implantation at either of 2 centers were included. LGE was defined by signal intensity ≥35% of maximal signal intensity, subdivided into core and border zones (≥50% and 35%-50% of maximal signal intensity, respectively), and categorized according to location (basal or nonbasal) and transmurality. ICD recordings and electrocardiograms were reviewed to determine the occurrence and type of ventricular arrhythmia during follow-up.
  
  
  RESULTS
  Of 87 patients (age 56 ± 13 y, 62% male, left ventricular ejection fraction 29% ± 12%), 55 (63%) had LGE (median 6.3 g, interquartile range 0.0-13.8 g). During a median follow-up of 45 months, monomorphic ventricular tachycardia (VT) occurred in 18 patients (21%) and polymorphic VT/ventricular fibrillation (VF) in 10 (11%). LGE predicted monomorphic VT (log-rank, P < .001), but not polymorphic VT/VF (log-rank, P = .40). The optimal cutoff value for the extent of LGE to predict monomorphic VT was 7.2 g (area under curve 0.84). Features associated with monomorphic VT were core extent, basal location, and area with 51%-75% LGE transmurality.
  
  
  CONCLUSIONS
  Myocardial scar assessed by LGE-CMR predicts monomorphic VT, but not polymorphic VT/VF, in NIDCM. The risk for monomorphic VT is particularly high when LGE shows a basal transmural distribution and a mass ≥7.2 g. Importantly, patients without LGE on CMR remain at risk for potentially fatal polymorphic VT/VF.
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Sebastiaan R D
authors.initials: SR
authors.lastname: Piers
authors.affiliation: Department of Cardiology, University Medical Centre Maastricht, Maastricht, The Netherlands.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Everaerts
authors.affiliation: Division of Image Processing, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
authors.affiliation: Department of Cardiology, University Medical Centre Maastricht, Maastricht, The Netherlands.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Hazebroek
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Hans-Marc
authors.initials: HM
authors.lastname: Siebelink
authors.affiliation: Department of Cardiology, University Medical Centre Maastricht, Maastricht, The Netherlands.
authors.forename: Laurent A F G
authors.initials: LA
authors.lastname: Pison
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.affiliation: Department of Cardiology, University Medical Centre Maastricht, Maastricht, The Netherlands.
authors.forename: Sebastiaan C A M
authors.initials: SC
authors.lastname: Bekkers
authors.affiliation: Department of Cardiology, University Medical Centre Maastricht, Maastricht, The Netherlands; Netherlands Heart Institute (ICIN), Utrecht, The Netherlands.
authors.forename: Stephane
authors.initials: S
authors.lastname: Heymans
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands. Electronic address: K.Zeppenfeld@lumc.nl.
authors.forename: Katja
authors.initials: K
authors.lastname: Zeppenfeld
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D002921:Cicatrix / Q000150:complications* / Q000473:pathology; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D014693:Ventricular Fibrillation; D016277:Ventricular Function, Left / Q000502:physiology
keywords: Cardiac magnetic resonance imaging; Dilated cardiomyopathy; Fibrosis; Implantable cardioverter-defibrillator; Late gadolinium enhancement; Nonischemic cardiomyopathy; Ventricular fibrillation; Ventricular tachycardia