Abstract 2692: Ajmaline Challenge in Patients Suspicious of Brugada Syndrome -Experience with 677 Patients
Intravenous ajmaline challenge is used to identify patients with Brugada syndrome if the diagnostic coved-type ECG pattern is not overt in the basal ECG. The aim of this study was to evaluate the diagnostic yield, safety and side effects of intravenous ajmaline challenge in 677 consecutive patients suspicious of Brugada syndrome. Patients and methods: In 677 patients (mean age 42 +/- 16 years, 394 males) suspicious of Brugada syndrome intravenous ajmaline was infused with a maximal dose of 1mg/kg body weight within 5–10 minutes under continuous ECG monitoring following the recommendation of the Brugada consensus conference. In 26 % of the cases the test was performed due to a syncope of unknown origin, in 16 % due to a basal saddle-back type ECG, in 45 % because of a family history of SCD (sudden cardiac death) or Brugada syndrome, in 2 % because of aborted SCD, and in 11 % due to other reasons. Results: In 262 patients (39 %) ajmaline challenge was positive with development of a diagnostic coved-type ECG. 26 % of the patients with a syncope of unknown origin revealed a positive ajmaline challenge and could be diagnosed with Brugada syndrome. In multivariable analyses, the Odds ratios for a positive response to ajmaline challenge was 2.5-fold for family history of Brugada syndrome, 2.6-fold for a basal saddle-back type ECG, 1.7-fold for a first degree AV-Block and 1.9-fold for male gender. 400 patients (59 %) received the maximal dose of ajmaline. In 3 % infusion of ajmaline was prematurely discontinued due to increase of the QRS duration and in 2 % due to premature ventricular extrasystoles. In one patient (0.1 %) non-sustained polymorphic VT were observed, which did not need further medical treatment. Another patient (0.1 %) developed ventricular fibrillation and needed single external defibrillation. Conclusions:
Ajmaline challenge can safely be performed under continuous monitoring during drug application. The risk of serious side effects using this protocol is very low (0.3 %).
In patients with a syncope of unknown origin ajmaline should be performed in order to rule out Brugada syndrome.
Clinical characteristics and electrocardiographical parameters may predict the positive response to ajmaline challenge.