title: Prognostic value of endocardial voltage mapping in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia.
abstract: BACKGROUND
  Endocardial voltage mapping (EVM) identifies low-voltage right ventricular (RV) areas, which may represent the electroanatomic scar substrate of life-threatening tachyarrhythmias. We prospectively assessed the prognostic value of EVM in a consecutive series of patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D).
  
  
  RESULTS
  We studied 69 consecutive ARVC/D patients (47 males; median age 35 years [28-45]) who underwent electrophysiological study and both bipolar and unipolar EVM. The extent of confluent bipolar (<1.5 mV) and unipolar (<6.0 mV) low-voltage electrograms was estimated using the CARTO-incorporated area calculation software. Fifty-three patients (77%) showed ≥1 RV electroanatomic scars with an estimated burden of bipolar versus unipolar low-voltage areas of 24.8% (7.2-31.5) and 64.8% (39.8-95.3), respectively (P=0.009). In the remaining patients with normal bipolar EVM (n=16; 23%), the use of unipolar EVM unmasked ≥1 region of low-voltage electrogram affecting 26.2% (11.6-38.2) of RV wall. During a median follow-up of 41 (28-56) months, 19 (27.5%) patients experienced arrhythmic events, such as sudden death (n=1), appropriate implantable cardioverter defibrillator interventions (n=7), or sustained ventricular tachycardia (n=11). Univariate predictors of arrhythmic outcome included previous cardiac arrest or syncope (hazard ratio=3.4; 95% confidence interval, 1.4-8.8; P=0.03) and extent of bipolar low-voltage areas (hazard ratio=1.7 per 5%; 95% confidence interval, 1.5-2; P<0.001), whereas the only independent predictor was the bipolar low-voltage electrogram burden (hazard ratio=1.6 per 5%; 95% confidence interval, 1.2-1.9; P<0.001). Patients with normal bipolar EVM had an uneventful clinical course.
  
  
  CONCLUSIONS
  The extent of bipolar RV endocardial low-voltage area was a powerful predictor of arrhythmic outcome in ARVC/D, independently of history and RV dilatation/dysfunction. A normal bipolar EVM characterized a low-risk subgroup of ARVC/D patients.
authors: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Medical School, Padova, Italy.
authors: Federico
authors: F
authors: Migliore
authors: Alessandro
authors: A
authors: Zorzi
authors: Maria
authors: M
authors: Silvano
authors: Michela
authors: M
authors: Bevilacqua
authors: Loira
authors: L
authors: Leoni
authors: Martina Perazzolo
authors: MP
authors: Marra
authors: Mohamed
authors: M
authors: Elmaghawry
authors: Luca
authors: L
authors: Brugnaro
authors: Carlo
authors: C
authors: Dal Lin
authors: Barbara
authors: B
authors: Bauce
authors: Ilaria
authors: I
authors: Rigato
authors: Giuseppe
authors: G
authors: Tarantini
authors: Cristina
authors: C
authors: Basso
authors: Gianfranco
authors: G
authors: Buja
authors: Gaetano
authors: G
authors: Thiene
authors: Sabino
authors: S
authors: Iliceto
authors: Domenico
authors: D
authors: Corrado
mesh_terms: D000200:Action Potentials; D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000150:complications / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D016009:Chi-Square Distribution; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D004699:Endocardium / Q000503:physiopathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009206:Myocardium / Q000473:pathology; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D056969:Voltage-Sensitive Dye Imaging