Physiologists have long been interested in the interaction, or coupling, between the heart and the vasculature. The early literature consists mainly of phenomenological descriptions of cardiac alterations resulting from specific interventions in the vasculature. Hundreds of studies, for example, describe functional aspects of hypertrophied myocardium associated with the excessive vascular loading produced by various types of experimental hypertension. Recently, the concepts of ventricular/vascular interaction have found important clinical application. The widespread use of vaso dilators and...