Although acute aortic rupture or dissection is relatively uncommon, it ranks in third
position among necropsy-confirmed causes of out-of-hospital sudden death in the general
population. Similar to other acute cardiovascular events (e.g., acute myocardial infarction,
sudden death, stroke, and pulmonary embolism) there is a growing body of evidence
regarding temporal patterns in onset, characterized by circadian, seasonal and weekly
variations for aortic aneurysms. On one hand, it is possible that these cardiovascular
diseases share common underlying pathophysiologic mechanisms, e.g., increase in blood
pressure, heart rate, sympathetic activity, basal vascular tone, vasoconstrictive
hormones, and prothrombotic tendency. On the other hand, the possibility exists that
the connecting link is an internal disruption (dyssynchrony) of some molecular mechanisms
intrinsic to the peripheral biological clock (that of cardiomyocyte is the most widely
investigated). Such disruption may contribute to cardiovascular disease and biological
rhythms - an intriguing hypothesis for future research.