title: Histologic findings in patients with clinical and instrumental diagnosis of sporadic arrhythmogenic right ventricular dysplasia.
abstract: OBJECTIVE
  We sought to analyze the histologic findings of 30 patients with a diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) based on established clinical and instrumental criteria, who did not have a family history of ARVD.
  
  
  BACKGROUND
  The diagnostic role of endomyocardial biopsy (EMB) in patients with a clinical profile of ARVD is still debated.
  
  
  METHODS
  Thirty patients (19 male, 11 female, mean age 27 +/- 10 years) with left bundle branch block morphology ventricular tachyarrhythmias and echocardiographic, angiographic, and magnetic resonance imaging (MRI) findings diagnostic of ARVD were studied. All patients, besides diagnostic, noninvasive, and invasive cardiac studies, underwent EMB in the apex, anterior free wall, inferior wall of the right ventricle (RV) and in the septal-apical region of the left ventricle.
  
  
  RESULTS
  Diagnostic histologic features of ARVD were found only in 9 (30%) patients and a myocarditis, according to the Dallas criteria, in the remaining 21 (70%) patients. Morphometric evaluation of RV samples showed significant differences in fatty tissue and myocyte percent area between ARVD and myocarditis (p < 0.001). Conversely, no difference was found between the two groups in arrhythmic patterns and structural and functional echocardiographic, angiographic, and MRI RV alterations. Magnetic resonance imaging showed hyperintense signals in 67% of ARVD and in 62% of myocarditis group (p = NS). During follow-up (mean, 23 +/- 14 months), all patients with myocarditis remained stable on antiarrhythmic therapy while five patients with ARVD required implantation of an implantable cardioverter defibrillator.
  
  
  CONCLUSIONS
  A myocarditis involving the RV can mimic ARVD. An EMB appears the most reliable diagnostic technique, with significant prognostic and therapeutic implications.
authors.affiliation: Cardio-Thoracic and Vascular Department, San Raffaele Hospital, Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Chimenti
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pieroni
authors.forename: Attilio
authors.initials: A
authors.lastname: Maseri
authors.forename: Andrea
authors.initials: A
authors.lastname: Frustaci
mesh_terms: D000293:Adolescent; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D001706:Biopsy; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000473:pathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007558:Italy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology / Q000648:ultrastructure; D011859:Radiography; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy
chemical_list: D000889:Anti-Arrhythmia Agents