Cardiac performance is regulated not only by cardiac muscle properties but also by several other factors, including those associated with the neurohumoral system and the mechanical characteristics of the peripheral circulation. New information con- cerning these regulatory factors has furthered our understanding of the pathophysi- ology of cardiac dysfunction. However, controversy remains, along with a need to integrate these multidisciplinary findings. It was with this in mind, together with my continuing interest in the response of the normal and diseased heart to variations in loading...