Lightning Learning: Long QT Syndrome
Congenital or acquired disorder which causes the QT interval to be prolonged (>450ms)
Genetic mutation affects Na and K channels
Drugs e.g. TCA, SSRIs, haloperidol and many more
Electrolyte disturbance e.g. hypokalaemia and hypocalcaemia
Prolonged repolarisation of the ventricles which causes arrhythmias. Diagnosed with aid of ECG and Schwartz criteria. Romano-Ward syndrome and Jervell and Lange-Nielsen syndrome are genetic forms of long QT syndrome.
Affects 1:2500 people worldwide. Patients may remain asymptomatic BUT Long QT syndrome is Associated with syncope, especially on exertion and... SUDDEN CARDIAC ARREST
It is often misdiagnosed as epilepsy. Management for congenital cases will be through lifestyle change, beta-blocker therapy and ICD. Patients will need to avoid extreme exertion.