There are multiple genetic mutations that account for long QT syndrome (LQTS), but LQT1, LQT2, and LQT3 account for 75% of cases of LQT.  Both LQT1 and LQT2 result from a mutation in the potassium channels; however, LQT1 results from a mutation in the alpha subunit of the slow delayed rectifier potassium channel while LQT2 is caused by a mutation in the alpha subunit of the slow delayed rectifier potassium channel. LQT3 is due to an abnormality in the sodium channels.
Long QT Syndrome classification
Short QT syndrome classification
Haff disease electrocardiogram
AVNRT classification
Pulseless ventricular tachycardia classification
Long QT Syndrome risk stratification
Hypertrophic cardiomyopathy classification
Stress cardiomyopathy classification