Positive Ajmaline provocation test for Brugada syndrome: acute and long-term outcomes

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. INTRODUCTION: Diagnosis of Brugada Syndrome (BrS) is established either by a observing a spontaneous Type 1 Brugada pattern on ECG or by unmasking Type 1 pattern with a drug challenge using a sodium channel blocker in suspected individuals. There are no clear indications on when to apply the Ajmaline provocation test and how to manage positive case. Data regarding the long-term outcome of this population is limited. The present study was designed to evaluate the incidence and identify predictors of arrhythmic events among subjects with Ajmaline induced Brugada ECG. OBJECTIVES: To evaluate the long-term outcomes of subjects diagnosed with drug induced Brugada ECG. METHODS: A multicenter international consecutive cohort including all cases of positive Ajmaline provocation test from 5 large electrophysiology centers form Israel, France, and Switzerland RESULTS: A total of 130 patients were recruited, the majority were males (70.8%) and Caucasian (97.7%). In our cohort the most frequent indication for performing an ajmaline test was a family history of BrS or sudden cardiac death (43.1%), then a suspicious ECG (38.5%), syncope (16.1%) and 3 with ventricular fibrillation (VF) (2.3%). The common infusion protocols used were 1mg/kg over 5 minutes (56%) and 1mg/kg over 10 minutes (26%). In all centers ajmaline infusion was stopped when type 1 Brugada pattern was observed. No adverse events occurred during the studies. All patients received instructions regarding the avoidance of arrhythmic triggers (specific drugs, alcohol and reduction of fever). During a median follow up time of 36 (7.5-66.9) months, 9 syncope occurred, 15 ICD (3 for secondary prevention because of VF as initial presentation) and 29 ILRs were implanted. No VF or deaths occurred in any of the study groups. CONCLUSION: In the present study of consecutive patients with a positive Ajmaline provocation test, there were no adverse outcomes during a median follow up of 3 years, irrespective of the indication for the test. Our results, indicating a low risk, are in agreement with the current ESC guidelines limiting the diagnosis of Brugada syndrome. Further research is warranted to test whether these patients maybe be managed safely solely by education to avoid arrhythmic triggers.