Frontiers in Cardiovascular Chrono-Biomedicine

Blood pressure and heart rate are the most important vital signs in diagnosing disease. Blood pressure evaluation in the clinic or in “out of office” situations using self and automated ambulatory blood pressure assessments are currently made using the traditional method introduced by Riva-Rocci in 1896. However, both blood pressure and heart rate are characterized by a high degree of variability short term from moment to moment, medium term over the normal day and night as well as in the very long term over months to years. Each of these provides different information about the autonomic, vascular and hormonal states of the individual and therefore provides potentially valuable information for the understanding of mechanisms leading to pathological conditions such as hypertension and cardiovascular disease. Clinical studies have clearly shown that blood pressure and heart rate variability is an important prognostic measure for predicting cardiovascular events. Importantly, there is a circadian pattern to the occurrence of acute cardiovascular events, such as myocardial ischemia, infarction, stroke and sudden death. Thus new approaches that target blood pressure variability such as chronotherapy have the potential to exploit the knowledge of circadian rhythms in order to reduce these events. The study of new mathematical algorithms to evaluate the variability of cardiovascular parameters has a high potential in the development of new methods for early detection of cardiovascular disease, to establish differential diagnosis with possible therapeutic consequences.

We now have a more sophisticated view of the physiological systems regulating circadian rhythms, which involve groups of specialized genes acting as key integrators of metabolism and behavior that synchronizes physiological processes. Circadian oscillators are present not only in the suprachiasmatic nucleus (SCN), which is considered as the master clock but also in peripheral tissues, including cardiovascular organs. Several animal studies are identifying roles for clock genes in cardiovascular physiology.

The study of pathophysiology and molecular mechanisms of circadian variability of cardiovascular systems in health and disease has the potential of leading to new diagnostic and/or therapies to treat cardiovascular and metabolic diseases. Studying the impact of circadian systems of the biological clock on human physiology will lead to a better understanding of inter-connections between genes, behavior and metabolic diseases. Investigations on the role of the circadian oscillation in searching at cellular and molecular levels offer new opportunities in the search for therapies based on mechanisms.
This research topic in Frontiers in Integrative Physiology calls for papers in any aspect of chrono-biomedicine: chronobiology to chronotherapy, analytical strategies and tools with papers extending from clinical to molecular investigations.