Cardiac sodium and calcium channels: a history of excitatory currents

The entire concept of ion channels as molecular machines to gate ion traffic across the membrane has only recently been generally recognized, even though ion channels are found in almost all cells. Na+ and Ca2+ channels are the basis of excitability, and in the heart they generate the rhythm, coordinating and controlling cardiac contraction. Dysfunction of ion channels results in arrhythmias that underlie 20-25% of deaths in the developed world, and some arrhythmias result directly from gene defects in ion channels. This is my personal perspective on the critical ideas and the pioneers in the field of cardiac Na+ and Ca2+ channels.