Sudden death.

Sudden, unexplained death through fibrillation, a mysterious heart disturbance that occurs without warning, is a worldwide phenomenon. Horizon's investigation begins in South East Asia and moves to Britain where 50,000 deaths annually are due to this cause. The programme looks at the geographical and circumstantial spread of the syndrome, taking in migrant workers in Singapore, voodoo deaths, cot deaths and the sudden death of young children caused by the shock of an alarm clock going off.