SADS stands for Sudden Arrhythmic Death Syndrome (In the past it has also been called Sudden Adult Death Syndrome or Sudden Death Syndrome but, because it affects infants and children too, the term Sudden Arrhythmic Death Syndrome is now used).
It is a term used to describe the likely cause of sudden death in someone when a post-mortem examination has not shown any other potential cause of death (structural heart disease and coronary disease or ‘hardening of the arteries’ have not been seen, or are not considered sufficient to cause sudden death).
Several conditions have been shown to cause SADS. These are usually electrical problems – problems with pump systems found in the walls of cells in the heart which are meant to pump salts in and out of the cell. These pump problems are called ‘channelopathies’ or ‘ ion channel disorders’ and can broadly be said to include ‘Long QT Syndrome’, Brugada syndrome, and the unpronounceable Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). It is not possible to find these at post-mortem (unless genetic tests are performed, which is not yet part of standard practice).