Over the last two decades, the analysis of blood pressure and heart rate variability has been increasingly used to obtain information on the mechanisms responsible for cardiovascular regulation in different physiological and pathological conditions. The evidence gathered so far has strongly supported the ability of this approach to provide unique insights into the factors involved in cardiovascular control. However, studies making use of these techniques have also underlined a number of problems concerning both the selection of the most appropriate analysis procedure to be used in a given situation and the interpretation of the results thus obtained.In this book volume leading experts from both the technological and the medical milieu have deeply addressed these issues. New tools for describing the regulation of the heart and the peripheral circulation in terms of 1/f processes, nonlinear and chaotic and complex systems have also been discussed. The overall result is a collection of contributions which provide the most recent development in this stimulating field.