Variable seasonal peaks for different types of aortic dissection?

Seasonal differences in the manifestation of cardiac death caused by arrhythmia, heart failure or acute myocardial infarction, with peaks during winter months, have been reported. Circadian patterns have also been shown for aortic dissection. A recent large population based study failed to find convincing statistical evidence of seasonal variability for ruptured aneurysms and dissections of the abdominal aorta. An analysis of 85 patients with non-traumatic rupture of the thoracic aorta found a higher occurrence during winter. However, there is little additional evidence from the literature that acute dissection of the thoracic aorta would be subject to cyclic variations throughout the year, although daily clinical practice suggests such seasonal variability in the occurrence of aortic dissection. Moreover, it is not known whether all types of aortic dissection follow the same pattern of incidence. Therefore, we reviewed all records of patients admitted to our hospital for acute dissection from autumn 1990 to summer 2001.