Brugada SyndromeBrugada syndrome is a genetic disorder that can cause a dangerous irregular heartbeat. When this happens, the lower chambers of your heart (ventricles) beat fast and irregularly. This prevents blood from circulating correctly in your body. This can be dangerous and may lead to fainting or even death, especially during sleep or rest. The disease has been called sudden, unexplained nocturnal death syndrome because people with it can often die in their sleep.