Long QT syndrome type 2: mechanism-based therapies

Long QT syndrome type 2 is a life-threatening disorder of cardiac electrophysiology. It can lead to sudden cardiac death as a result of QT prolongation and can remain undetected until it presents clinically in the form of life-threatening cardiac arrythmias. Current treatment relies on symptom management largely through the use of β-adrenergic blockade and presently no mechanism-based therapies exist to treat the dysfunction in the channels responsible for the rapid delayed rectifier K current which is the pathological source of long QT syndrome type 2. We review the pathophysiology, diagnosis and current management of this life-threatening condition and also analyze some promising potential mechanism-based therapies. Long QT syndrome is a condition which is characterized by an abnormally lengthened time period of electrical activity in the heart. This abnormality can result in the initiation of heart rhythms which can cause the patient to lose consciousness or cause the patient to enter a heart rhythm which is not conducive to life resulting in sudden cardiac death. In this article we look more closely at a subtype of this disease known as long QT syndrome type 2. We look at how this disease can cause sudden cardiac death, how it is currently managed and how future treatments may be able to work at a genetic and cellular level to reverse the disease-causing mechanisms behind this life-threatening syndrome.