Brugada syndrome is a rare, genetic condition that can disrupt your heart rhythm. It can cause dizziness or, in serious cases, cardiac arrest. Your heartbeat is controlled by electrical impulses. This causes your heart to beat regularly and pump blood round your body. In Brugada syndrome, although your heart structure is usually normal, there is a disturbance of the electrical activity in your heart. This can cause an abnormal heart rhythm (arrhythmia) which can be fatal. If you have Brugada syndrome, you’re more likely to develop a dangerous arrhythmia if you have a fever (high body temperature) or if you’re exposed to some specific medicines.