Seasonal variation in mortality from myocardial infarction and haemopericardium. A postmortem study

Seasonal variation in the incidence of and mortality from myocardial infarction (MI) has been well recognised for many years. Haemopericardium (HP) is usually a fatal complication of MI. No data exist in the literature with regard to the seasonal variation in mortality from HP.

To perform a necropsy based study to confirm seasonal variation in mortality from MI in a London population and to determine whether seasonal variation in mortality from HP can be established.

Postmortem causes of death issued by several pathologists, working in two public London mortuaries over a five year period from 1999 to 2004 were analysed. Deaths caused by HP secondary to traumatic or iatrogenic causes were specifically excluded, as were deaths caused by HP secondary to bicuspid aortic valve and aortic dissection. The results were subdivided into winter (1 November to 31 March) and summer (1 April to 31 October).

In total, there were 2266 cases of MI and 135 cases of HP. Significantly more deaths from HP (83 of 135; 61.5%; p = 0.004) and MI (1051 of 2266; 46.4%; p = 0.016) occurred in the five month winter period. Furthermore, there was a significantly higher incidence of HP compared with MI during the winter (83/1051; 7.9%) than the summer (52/1215; 4.3%; p<0.001). There was no significant difference in the age or sex of patients dying in either the winter or summer.

There is seasonal variation in mortality from both MI and HP in the London population, as confirmed by a postmortem study.