title: Lack of uniform progression of endocardial scar in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy and ventricular tachycardia.
abstract: BACKGROUND
  The endocardial substrate for ventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is thought to be caused by a progressive degenerative process. Many clinical decisions and treatment plans are guided by this pathophysiologic assumption, but the extent of progression of macroscopic endocardial scar and right ventricular (RV) dilatation have not been assessed.
  
  
  RESULTS
  Eleven patients with ARVD/C and ventricular tachycardia had 2 detailed sinus rhythm electroanatomic endocardial voltage maps (average, 291+/-122 points per map; range, 114 to 558 points) performed a mean of 57 months apart (minimum, 9 months) as part of ventricular tachycardia ablation procedures. Voltage-defined scar (<1.5 mV) and RV volume were measured by area and volume measurement software and compared. Two of the 11 patients had a clear increase in scar area (47 cm(2); 32 cm(2)) confirmed by visual inspection. The remaining 9 (81%; 95% CI, 48% to 98%) patients had no increase (<10-cm(2) difference) in scar area between studies. In contrast, 10 of the 11 patients had a significant increase in RV volume, with an average increase of 24% (212+/-67 mL to 263+/-52 mL; P< or =0.01).
  
  
  CONCLUSIONS
  In patients with ARVD/C and ventricular tachycardia, progressive RV dilatation is the rule, and rapid progression of significant macroscopic endocardial scar occurs in only a subset of patients. These results have important management implications, suggesting that efforts to prevent RV dilatation in this population are needed and that an aggressive substrate-based ablation strategy offers the potential to provide long-term ventricular tachycardia control.
authors.affiliation: Section of Cardiac Electrophysiology, Cardiovascular Division, Department of Medicine, Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Riley
authors.forename: Erica
authors.initials: E
authors.lastname: Zado
authors.forename: Rupa
authors.initials: R
authors.lastname: Bala
authors.forename: David J
authors.initials: DJ
authors.lastname: Callans
authors.forename: Joshua
authors.initials: J
authors.lastname: Cooper
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dixit
authors.forename: Fermin
authors.initials: F
authors.lastname: Garcia
authors.forename: Edward P
authors.initials: EP
authors.lastname: Gerstenfeld
authors.forename: Mathew D
authors.initials: MD
authors.lastname: Hutchinson
authors.forename: David
authors.initials: D
authors.lastname: Lin
authors.forename: Vickas
authors.initials: V
authors.lastname: Patel
authors.forename: Ralph
authors.initials: R
authors.lastname: Verdino
authors.forename: Francis E
authors.initials: FE
authors.lastname: Marchlinski
mesh_terms: D000293:Adolescent; D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000150:complications / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation; D002921:Cicatrix / Q000209:etiology / Q000473:pathology*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D004699:Endocardium / Q000473:pathology*; D005260:Female; D006801:Humans; D017380:Hypertrophy, Right Ventricular / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012086:Reoperation; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D014945:Wound Healing