Abstract 2695: Comparison of the Full Stomach Test and a Pharmacological Test in Unmasking Brugada Syndrome
Background: The electrocardiogram (ECG) feature of Brugada syndrome is dynamic and often concealed, but it is well known that sodium channel blockers may unmask its concealed forms. Recently, the full stomach test has been introduced as a novel diagnostic technique for identifying patients at risk of Brugada syndrome. In this study, we compared diagnostic value in unmasking Brugada syndrome between the full stomach test and a pharmacological test.
Methods: We enrolled 57 consecutive patients with Brugada-type ECGs, showing persistent or transient coved ST segment elevation ≥0.2 mV in leads V1-V2. Pilsicainide, a pure sodium channel blocker, was used as a pharmacological test. Patients were given an oral dose of 100 mg of pilsicainide, and a 12-lead ECG was recorded 1 hour later. The pharmacological test was defined as positive when criteria from the consensus report on Brugada syndrome were fulfilled. For a full stomach test, patients had a large meal with beverages, and a 12-lead ECGs was recorded within 30 minutes after meals. The full stomach test was defined as positive when augmentation of ST segment elevation or visible T-wave variation in leads V1-V3 was observed after meals. We divided patients into two groups (i.e., high risk group [n=27] and indeterminate risk group [n=30]). Patients who had a history of life-threatening events and/or a family history of sudden death were defined as high risk group.
Results: Both tests were successfully done in all patients. The pharmacological test was positive in 39 patients (68%) and the full stomach test was positive in 25 patients (44%). In both tests, the incidence (85% and 70%, respectively) of positive outcomes in high risk group was significantly higher than that (53% and 20%, respectively) of indeterminate risk group. In comparison between the two tests, the full stomach test was characterized by a more significant association with positive outcomes than that of the pharmacological test (P=0.0004, odds ratio=9.5 vs. P=0.02, odds ratio=5.0).
Conclusions: In unmasking Brugada syndrome, a large meal is more effective than a sodium channel blocker. These data may support an idea that autonomic nerve modulation, particularly high vagal tone, plays an important role in arrhythmogenesis of the syndrome.