Although it is widely recognized that there are significant

variations in the circulation throughout the 24-hour day,

these patterns have often been conceived as nuisance

variables rather than functional differences.

Responses of the circulation are examined here not as stable

phenomena, but as integrated functions highly sensitive to

environmental conditions, and driven by internal and

external pacesetters. In this volume, cardiologists with a

primary interest in hypertension or heart disease,

chronobiologists, and psychologists join together for the

first time to give the reader the opportunity to learn the

extent and clinical significance of these changes from a

chronobiological, behavioral and physiological perspective.