A standardized ajmaline challenge using fractionated intravenous administration safely unmasked Brugada syndrome in 23% of patients, with symptomatic ventricular tachycardia occurring in only 1.3%.
Observational (n=158)
No
Does a standardized fractionated ajmaline challenge safely unmask the diagnostic ECG pattern in patients suspected of Brugada syndrome?
A standardized ajmaline challenge with fractionated intravenous administration is a safe and effective method to unmask Brugada syndrome, though it carries a small risk of inducing ventricular tachycardia requiring continuous medical surveillance.
AIMS: 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. METHODS AND 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. CONCLUSION: 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.
Sascha Rolf (Mon,) conducted a observational in Brugada syndrome (n=158). Ajmaline challenge was evaluated on Unmasking of typical coved-type ECG pattern of Brugada syndrome. A standardized ajmaline challenge using fractionated intravenous administration safely unmasked Brugada syndrome in 23% of patients, with symptomatic ventricular tachycardia occurring in only 1.3%.
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