Congenital long QT syndrome: a clinician's guide

Congenital long QT syndrome (LQTS) is a familial cardiac ion channelopathy first described over 60 years ago. It is characterised by prolonged ventricular repolarisation (long QT on electrocardiography), ventricular arrhythmias and associated syncope or sudden cardiac death. As the most closely studied cardiac channelopathy, over the decades we have gained a deep appreciation of the complex genetic model of LQTS. Variability in genetic expression and incomplete penetrance leads to a heterogeneous phenotype that can be challenging to classify clinically. In recent times, progress has been made in diagnostic method, risk stratification and treatment options. This review has been written as a guide for the general cardiologist to understand the basic pathophysiology, diagnosis and management priorities for the most encountered LQTS subtypes: LQT1, LQT2 and LQT3.