Cardiac ion channels in health and disease.
Cardiac electrical activity depends on the coordinated propagation of excitatory stimuli through the heart and, as a consequence, the generation of action potentials in individual cardiomyocytes. Action potential formation results from the opening and closing (gating) of ion channels that are expressed within the sarcolemma of cardiomyocytes. Ion channels possess distinct genetic, molecular, pharmacologic, and gating properties and exhibit dissimilar expression levels within different cardiac regions. By gating, ion channels permit ion currents across the sarcolemma, thereby creating the different phases of the action potential (e.g., resting phase, depolarization, repolarization). The importance of ion channels in maintaining normal heart rhythm is reflected by the increased incidence of arrhythmias in inherited diseases that are linked to mutations in genes encoding ion channels or their accessory proteins and in acquired diseases that are associated with changes in ion channel expression levels or gating properties. This review discusses ion channels that contribute to action potential formation in healthy hearts and their role in inherited and acquired diseases.
Amin
Ahmad S
AS
Heart Failure Research Center, University of Amsterdam, Amsterdam, The Netherlands.
Tan
Hanno L
HL
Wilde
Arthur A M
AA
D000200:Action Potentials / Q000502:physiology*; D001281:Atrial Fibrillation / Q000235:genetics / Q000503:physiopathology; D001283:Atrioventricular Node / Q000502:physiology / Q000503:physiopathology; D053840:Brugada Syndrome / Q000235:genetics / Q000503:physiopathology; D000242:Cyclic AMP; D006329:Heart Conduction System / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D007473:Ion Channels / Q000502:physiology*; D008133:Long QT Syndrome / Q000235:genetics / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000502:physiology*; D012307:Risk Factors; D012508:Sarcolemma / Q000502:physiology
D007473:Ion Channels; D000242:Cyclic AMP