title: The importance of class-I antiarrhythmic drug test in the evaluation of patients with syncope: unmasking Brugada syndrome.
abstract: BACKGROUND
  The Brugada syndrome (BrS) can first present with syncope. Class-I antiarrhythmic drug (AAD) test is used to unmask the diagnostic coved-type ECG pattern in case it is not spontaneously present. The aim of the study was to analyze patients with BrS presenting with syncope as first manifestation and compare patients with syncope and a spontaneous coved-type ECG to patients with syncope in whom a class-I AAD test unmasked the disease.
  
  
  RESULTS
  Fifty-eight of 157 probands (36.9%) had syncope as first manifestation of the disease. Twenty-six patients (44.8%, group A) showed a spontaneous coved-type ECG diagnostic for BrS at first presentation. In 32 patients (55.2%, group B) without spontaneous coved-type ECG pattern at first presentation (36% normal ECGs and 19% type-II ECG pattern), a class-I AAD test unmasked the disease. Twenty-one patients of group A and 29 patients of group B underwent implantable cardioverter defibrillator (ICD) implantation. The mean follow up as 9.7 ± 55.7 month. Four patients in group A (15.4%) and 3 patients (9.3%) in group B had appropriate ICD shock delivery due to ventricular fibrillation or ventricular tachycardia (P = NS).
  
  
  CONCLUSIONS
  One of 3 patients with BrS presents first with syncope. More than one-third of these patients have a normal ECG at investigation for syncope and the correct diagnosis would have been missed without a class-I AAD test. Patients presenting with syncope are at similar risk irrespective of the presence of a spontaneous coved-type ECG.
authors: Heart Rhythm Management Center, Vrije Universiteit Brussel, Belgium, UK. roosmarkus@bluewin.ch
authors: Markus
authors: M
authors: Roos
authors: Andrea
authors: A
authors: Sarkozy
authors: Jeannette
authors: J
authors: Brodbeck
authors: Stefan
authors: S
authors: Henkens
authors: Gian-Battista
authors: GB
authors: Chierchia
authors: Carlo
authors: C
authors: de Asmundis
authors: Lucio
authors: L
authors: Capulzini
authors: Stephan Andreas
authors: SA
authors: Müller-Burri
authors: Yoshi
authors: Y
authors: Yakazi
authors: Pedro
authors: P
authors: Brugada
mesh_terms: D000328:Adult; D000889:Anti-Arrhythmia Agents; D053840:Brugada Syndrome / Q000175:diagnosis*; D016757:Death, Sudden, Cardiac; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D055724:Electrophysiological Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012042:Registries; D013575:Syncope / Q000175:diagnosis*; D017180:Tachycardia, Ventricular / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents