[Influence of circadian rhythms on cardiovascular function].

The clinical importance of circadian biological rhythms has been strengthened by a number of studies showing a circadian distribution of cardiovascular events like myocardial infarction, stroke, complex arrhythmia, or sudden cardiac death. Incidence of diseases showed a maximum during the early morning hours after awakening from sleep. In addition, a number of pathophysiological mechanisms has been identified to coincide with this peak including blood pressure and heart rate surges, decreased endothelial dilatory capacity of peripheral and coronary arteries, enhanced sympathetic activity, decreased cardiac electrical stability, and increased platelet aggregation. This time window of high risk for the incidence of cardiovascular events has been identified as a target for new treatment and prevention strategies including new release forms of antihypertensive and coronary-dilatory drugs. The use of melatonin as an antihypertensive drug has been successfully explored and opens new opportunities for the management of cardiovascular dysfunction and disease from a circadian perspective.