title: The ajmaline challenge in Brugada syndrome: diagnostic impact, safety, and recommended protocol.
abstract: OBJECTIVE
  The diagnostic ECG pattern in Brugada syndrome (BS) can transiently normalize and may be unmasked by sodium channel blockers such as ajmaline. Proarrhythmic effects of the drug have been well documented in the literature. A detailed protocol for the ajmaline challenge in Brugada syndrome has not yet been described. Therefore, we prospectively studied the risks of a standardized ajmaline test.
  
  
  RESULTS
  During a period of 60 months, 158 patients underwent the ajmaline test in our institution. Ajmaline was given intravenously in fractions (10mg every two minutes) up to a target dose of 1mg/kg. In 37 patients (23%) the typical coved-type ECG pattern of BS was unmasked. During the test, symptomatic VT appeared in 2 patients (1.3%). In all other patients, the drug challenge did not induce VT if the target dose, QRS prolongation >30%, presence/appearance of the typical ECG, or the occurrence of premature ventricular ectopy were considered as end points of the test. A positive response to ajmaline was induced in 2 of 94 patients (2%) with a normal baseline ECG, who underwent evaluation solely for syncope of unknown origin.
  
  
  CONCLUSIONS
  The ajmaline challenge using a protocol with fractionated drug administration is a safe method to diagnose BS. Because of the potential induction of VT, it should be performed under continuous medical surveillance with advanced life-support facilities. Due to the prognostic importance all patients with aborted sudden death or unexplained syncope without demonstrable structural heart disease and family members of affected individuals should presently undergo drug testing for unmasking BS.
authors.affiliation: Hospital of the Westfälische Wilhelms-University, Department of Cardiology and Angiology, Institute for Arteriosclerosis Research, Münster, Germany. srolf@uni-muenster.de
authors.forename: Sascha
authors.initials: S
authors.lastname: Rolf
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Bruns
authors.forename: Thomas
authors.initials: T
authors.lastname: Wichter
authors.forename: Paulus
authors.initials: P
authors.lastname: Kirchhof
authors.forename: Michael
authors.initials: M
authors.lastname: Ribbing
authors.forename: Kristina
authors.initials: K
authors.lastname: Wasmer
authors.forename: Matthias
authors.initials: M
authors.lastname: Paul
authors.forename: Günter
authors.initials: G
authors.lastname: Breithardt
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
authors.forename: Lars
authors.initials: L
authors.lastname: Eckardt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000404:Ajmaline / Q000008:administration & dosage / Q000009:adverse effects; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects; D002037:Bundle-Branch Block / Q000175:diagnosis*; D002648:Child; D002985:Clinical Protocols; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000379:methods; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D013575:Syncope / Q000209:etiology*; D013577:Syndrome
chemical_list: D000889:Anti-Arrhythmia Agents; D000404:Ajmaline