Ajmaline challenge for the diagnosis of Brugada syndrome: which protocol?
Elise Arnalsteen-Dassonvalle1, Jean-Sylvain Hermida, Maciev Kubala
1Centre d'activité de rythmologie, Amiens-Picardie University Hospital, 80054 Amiens cedex 1, France.
Background:
Ajmaline challenge is commonly used for the diagnosis of Brugada syndrome. A slow infusion rate has been recommended in view of the proarrhythmic risk, but the diagnostic value of various infusion rates has not been investigated.
Aims:
To compare rapid and slow ajmaline infusion rates and to assess the proarrhythmic risk.
Methods:
The first part of this study prospectively compared rapid and slow infusion rates in terms of results and ventricular arrhythmias. Thirty-two patients (mean age 41±12 years; 26 men) received the two ajmaline challenges on different days. According to randomization, ajmaline (1 mg/kg) was infused at 1 mg/sec or over 10 minutes. The second part of the study retrospectively assessed the prevalence of ventricular arrhythmia during 386 challenges performed at a rapid infusion rate.
Results:
No differences were observed between rapid and slow tests. All patients diagnosed as positive or negative with one test obtained the same result with the other test. Ventricular premature beats were observed in five of 32 patients during the slow challenge and in four of 32 patients during the rapid challenge. No sustained ventricular arrhythmias were observed. Analysis of the 386 tests revealed four episodes of ventricular arrhythmia (two complex ventricular premature beats, one non-sustained ventricular tachycardia and one ventricular fibrillation).
Conclusion:
Slow and rapid infusions of ajmaline have identical diagnostic performances on suspected Brugada electrocardiograms. Owing to the risk of severe proarrhythmia, a slow infusion rate, allowing early discontinuation, should be recommended.
Insights
Rapid and slow ajmaline infusions show similar diagnostic accuracy for Brugada syndrome. A slow infusion is recommended due to reduced proarrhythmic risk during ajmaline challenge testing.
Area of Science:
- Cardiology
- Clinical Electrophysiology
Background:
- Ajmaline challenge is a standard diagnostic tool for Brugada syndrome.
- Current guidelines recommend slow ajmaline infusion due to potential proarrhythmic risks.
- The diagnostic efficacy of different ajmaline infusion rates remains under-investigated.
Purpose of the Study:
- To compare the diagnostic performance of rapid versus slow ajmaline infusion rates.
- To evaluate and compare the proarrhythmic risks associated with different infusion rates.
Main Methods:
- Prospective comparison of rapid (1 mg/sec) and slow (10 minutes) ajmaline infusion (1 mg/kg) in 32 patients.
- Retrospective analysis of ventricular arrhythmias during 386 ajmaline challenges at a rapid infusion rate.
- Patients underwent both rapid and slow ajmaline challenges on separate days.
Main Results:
- No significant differences in diagnostic outcomes between rapid and slow ajmaline infusion rates were observed.
- Consistent diagnostic results (positive/negative) were obtained with both infusion methods.
- Ventricular arrhythmias were infrequent and mild, with no sustained arrhythmias reported in the prospective arm; four episodes occurred in the retrospective arm.
Conclusions:
- Both rapid and slow ajmaline infusions demonstrate equivalent diagnostic accuracy for Brugada syndrome.
- A slow infusion rate is advisable to mitigate proarrhythmic risks and allow for timely intervention.
- The study supports the continued use of ajmaline challenge testing with a preference for slower administration.
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