Should all individuals with a nondiagnostic Brugada-electrocardiogram undergo sodium-channel blocker test
Heart Rhythm, 05/24/2012
Zorzi A et al. – In asymptomatic individuals with a nondiagnostic Brugada–electrocardiogram (Br–ECG), the incidence of events is low regardless of the sodium–channel blocker test result while in symptomatic patients a positive sodium–channel blocker test result is associated with an adverse arrhythmic outcome and may contribute to risk stratification.Methods
- The authors studied 153 consecutive patients (128 men; age 41.7 ± 14.0 years) with a type 2/3 Br–ECG who underwent a sodium–channel blocker test with either flecainide (48%) or ajmaline (52%).
- Nondiagnostic Br–ECGs were identified during the evaluation of cardiac arrest in 5 patients (3%), syncope in 36 (24%), cascade family screening in 48 (31%), and incidental ECG in 64 (42%).
- A spontaneous type 1 Br–ECG was systematically excluded by serial ECGs (6.1 ± 0.4) and recording of right precordial leads both at standard and second and third intercostal spaces.
- The sodium–channel blocker test result was positive in 76 (50%) patients.
- During a follow–up of 59 ± 33 months, 9 (5.9%) patients experienced events such as syncope (n = 4), appropriate interventions of defibrillator (n = 4), or sudden death (n = 1).
- A positive sodium–channel blocker test was associated with a significantly higher event rate in symptomatic patients (P = .01) but not in asymptomatic individuals (P = .18).
- No events occurred among asymptomatic individuals with an incidental nondiagnostic Br–ECG.