This monograph contains 20 selected papers presented at the Symposium on Subcellular Basis of Contractile Failure which was held in Ottawa during May 11-13, 1989 and is designed for the benefit ofthose who were unable to attend this event. It is now increasingly becoming clear that an excessive amount of calcium is intimately involved in the pathogenesis of a wide variety of heart diseases. Accordingly, the investigations concerning the role of calcium chan nels and their regulatory mechanisms in heart function as well as of the intra cellular calcium overload in cardiac dysfunction are...