Cellular basis for inotropic changes in the heart.

Cardiac contraction is a highly regulated process that involves nearly every aspect of the cardiac cell function. Many steps in the process are regulated by the cell to optimize contraction, and these can often be modified to benefit the patient with heart damage. These include the action potential, calcium channels, release and uptake of cellular calcium, sensitivity of contractile proteins to calcium, and energy utilization. A dramatic expansion of our understanding of these cellular contractile and regulatory processes gives us an unprecedented opportunity to devise new ways of modifying cardiac contraction to the benefit of our patients.