Abstract 2693: The Effects of Eating Meals on the ST-RR Relationship in Patients with Brugada Syndrome
In patients with Brugada syndrome, the circadian variation of ST elevation could be modulated by the autonomic nervous activity and the RR interval. Recently, glucose-induced insulin secretion was also reported to be a modulating factor of ST elevation. So, we assessed the effects of eating a meal on the ST-RR relationship in the daily lives of patients with Brugada syndrome.
Methods: Twenty-five consecutive male patients with Brugada syndrome who had type I ST elevation were categorized into 12 symptomatic (group S) and 13 asymptomatic (group AS) groups. Unipolar V2 lead digital Holter ECG was recorded, and the ST level was automatically measured. The ST-RR relationships were analyzed for 2 hours before and after every meal. From the ST-RR linear regression lines, the ST-RR slope (mm/sec) and ST (mm) at RR intervals of both 0.8 sec and 1.2 sec (ST(0.8) and ST(1.2)) were determined.
Results: The ST-RR slope increased significantly after lunch (2.6±0.4 vs. 4.4±1.2, p<0.05) and dinner (2.1±1.0 vs. 5.2±1.9, p<0.01) in group S; however, it didn’t in group AS. In both groups, ST(0.8) was not different between before and after every meal. However, ST(1.2) increased after every meal in group S, and it increased only after lunch in group AS. After dinner, ST(1.2) was significantly higher in group S than group AS (5.0±2.7 vs. 3.6±0.8, p<0.05). An increase in both the ST-RR slope and ST(1.2) after a meal was highest at dinner in group S.
Conclusions: In symptomatic patients with Brugada syndrome, bradycardia-dependent augmentation of ST elevation was enhanced after eating a meal, especially after dinner. This could be related to an occurrence of ventricular fibrillation in the late evening.