Ion channelopathies (inherited heart rhythm disturbance)

Ion channelopathies (inherited heart rhythm disturbance)

The medical term for an inherited heart rhythm disturbance is ion channelopathies which is a group of uncommon diseases that can cause
life-threatening arrhythmias. An arrhythmia is a disturbance in the heart's electrical system.

Ion channelopathies are uncommon genetic conditions that are caused by abnormalities of the DNA, known as 'mutations'. They are usually
inherited from parents, although they can occur for the first time in a family. If they occur for the first time in a single family member they are
described as 'sporadic'.

The mutations affect certain genes - specific segments of the DNA that are responsible for the production of 'ion channels' in the heart.

An ion is a chemical substance - such as sodium or potassium - that carriesan electrical charge and forms the basis of the movement of electricity
through the heart muscle.

An ion channel is the route that the ions take in and out of the heart muscle cells to allow the movement of electricity.

The ion channels regulate the flow of electrical charge. If these channels don't behave normally, the electrical function of the heart becomes abnormal.

The person can then be prone to arrhythmias (disturbances in the heart's rhythm) that can cause blackouts, cardiac arrest and in some cases sudden
death. If a sudden death due to ion channelopathy occurs then there isno evidence of an abnormality when a post-mortem is performed.

If no other cause can be found then this is termed Sudden Arrhythmic Death Syndrome (SADS).

Ion channelopathies affect the electrical functioning of the heart without affecting the heart's structure. There are several different types of ion
channelopathies including:

  • Long QT Syndrome (LQTS)
  • Brugada Syndrome
  • CPVT (catecholaminergic polymorphic ventricular tachycardia)
  • PCCD (progressive cardiac conduction defect)
  • Short QT syndrome (SQTS)
  • Familial atrial fibrillation
  • Sodium channel disease.

If you have been diagnosed with an ion channelopathy you will need to have an assessment to determine your risk of sudden death.