Sudden Arrhythmic Death Syndrome (SADS)

What is SADS?

SADS (Sudden Arrhythmic Death Syndrome) is when someone passes away suddenly as a result of cardiac arrest, but the cause of it cannot be determined. A cardiac arrest is when the heart suddenly stops beating.

SADS can cause sudden death in young and otherwise healthy people. According to the British Heart Foundation, SADS affects around 500 people in the UK each year.

The rhythm of the heart is controlled by electrical signals. If something happens to these signals, it can cause an arrhythmia (abnormal heart rhythm). Some arrhythmias, if left untreated, have the potential to cause a cardiac arrest.

What causes it?

SADS happens when an arrhythmia is left untreated, and leads to cardiac arrest. There are a number of conditions that can cause SADS, however after death these can be very difficult to diagnose as the heart appears normal.

Some of the inherited conditions include:

  • Long QT syndrome – when the electrical system controlling the heart is impacted by delays
  • Brugada syndome
  • Catecholaminergic polymorphic ventricular tachycardia
  • Progressive cardiac conduction defect

Other conditions include:

  • Hypertrophic cardiomyopathy – in which the heart muscle is abnormally thick
  • Dilated cardiomyopathy
  • Arrhythmic right ventricular cardiomyopathy