Brugada syndrome is a condition that causes a disruption of the heart's normal rhythm. Specifically, this disorder can lead to uncoordinated electrical activity in the heart's lower chambers (ventricles), an abnormality called ventricular arrhythmia. If untreated, the irregular heartbeats can cause fainting (syncope), seizures, difficulty breathing, or sudden death. These complications typically occur when an affected person is resting or asleep.