Seasonal variation in the occurrence of nontraumatic rupture of thoracic aorta

Research has identified circadian and seasonal patterns for several acute c ardiovascular diseases. In order to investigate the possible existence of a seasonal variation in the onset of acute nontraumatic ruptures of thoracic aorta, this study considered all patients referred to the emergency depart ment of St Anna Hospital of Ferrara, Italy from January 1985 to December 19 96. In the considered period, 85 patients (52 males, 33 females) of nontrau matic ruptures of thoracic aorta were observed. Cosinor analysis and partia l Fourier series with up to 4 harmonics were applied to monthly data, and t he best fitting curves for circannual rhythmicity were calculated. A higher winter occurrence with a significant peak in January was found far the tot al population and the male subgroup. Although the underlying factors are no t fully known, such patterns strictly resemble that of arterial blood press ure. Emergency doctors can put to practical use the recognition of a clearl y identified chronorisk for aortic rupture, increasing alertness, and provi ding the most effective antihypertensive protection at the specific vulnera ble periods. (Am J Emerg Med 1999;17:672-674 Copyright (C) 1999 by W.B, Sau nders Company).