Vascular emergencies: what's in season?

Seasonality in ischaemic coronary artery disease is well documented with a winter/summer variation the commonest pattern. The influence of seasonal variation on events in other vascular territories is less well documented. The incidence of ruptured abdominal aortic aneurysm and emergency lower-limb ischaemia was analysed on a monthly basis over a 5-year period. A total of 372 ruptured abdominal aortic aneurysms occurred with a peak incidence in spring and autumn; however, no seasonal pattern was seen in the rate of emergency admissions with lower-limb ischaemia (n = 606). The explanation for this seasonal pattern in ruptured aneurysms is unknown. The haemodynamic adjustments to changes in climate require further study.