Drug challenge
The sodium channel blocker drug of choice was Ajmaline, which was
administered intravenously. The protocol infusion was 10mg every two
minutes up to a target dose of 1mg/kg. The test was considered positive
if the abnormal coved type-1 ECG pattern appeared in the right
precordial leads V1 and/or V2 positioned in the second, third or fourth
intercostal space. Ajmaline challenge was interrupted before reaching
the target dose in the following situations: QRS prolongation exceeding
30% compared to baseline interval, an early typical Brugada type-1 ECG
aspect, and in case of premature ventricular beats and/or high-degree
atrioventricular block occurrence.1