The role of the slow delayed rectifier potassium channel in cardiac physiology

Tntroduction. The [alpha]-subunit (KCNQl) and auxiliary [beta]-subunit (KCNEl) form the slow delayed rectifier potassium channel (IKs)' Although the IKs current is considered to be involved in repolarisation of the cardiac action potential the exact role of IKs in cardiac physiology is still unclear. Recent studies have suggested that IKs is involved as a repolarisation reserve. However, inherited mutations in KCNQl and KCNEI genes suggest that IKs has a prominent role in normal cardiac repolarisation. Understanding the role of IKs in human cardiac physiology may lead to improvements in the treatment of arrhythmias. The aim of this project was to assess the extent to which the cardiac IKs current is involved in excitation-contraction coupling and whether modification of the IKs CUlTent can be of therapeutic benefit in treatment of ventricular arrhythmias.