We investigated breathing patterns and the occurrence of arrhythmias and ST-segment
changes during sleep in patients with Brugada syndrome. Patients with Brugada syndrome
are more likely to die from ventricular arrhythmias during sleep. ST-segment changes
have been correlated with risk of sudden cardiac death. Whether sleep disturbances
may contribute to arrhythmogenesis is unknown. Patients with Brugada syndrome underwent
overnight polysomnography with simultaneous 12-lead electrocardiographic recording.
A control group matched by age, gender, and body mass index (BMI) also underwent polysomnography.
Twenty patients were included (50 ± 15 years old, 75% men). Despite their normal BMI
(24.7 ± 2.7 kg/m(2)), 45% had sleep-disordered breathing (SDB), with a mean apnea-hypopnea
index of 17.2 ± 14 events/hour. In patients with a high risk of arrhythmias, 5 (63%)
had SDB. In the control group, 27% had SDB. Atrial or ventricular arrhythmias were
not observed. Spontaneous ST-segment changes occurred in 2 patients over 45 different
time points. Most ST-segment changes were observed during rapid eye movement sleep
(31%) or within 1 minute of arousals (44%). Regarding respiratory events, 25 (56%)
of ST-segment changes were related to occurrence of apnea or hypopnea. In conclusion,
patients with Brugada syndrome have a high prevalence of SDB even in the setting of
normal BMI. The higher incidence of nocturnal death in patients with Brugada syndrome
may be conceivably related to co-morbid SDB. Moreover, autonomic instability encountered
in rapid eye movement sleep and arousals could potentiate the risk of arrhythmias.