Changes in the ambient temperature (esp. warm to cold) as well as exercise are triggers for vasospasms and plaque rupture. Weather data (temperature, precipitation in general as well as snowfall and changes in atmospheric pressure) will be correlated with the incidence of myocardial infarctions.

Besides classical cardiovascular risk factors such as smoking, obesity, elevated cholesterol levels and diabetes there are also acute factors potentially triggering acute coronary events. The impact of air temperature (changes) or humidity are of potential relevance. In addition, exercise and the associated increase in oxygen demand of the myocardium and blood pressure is another trigger for plaque rupture and the acute onset of myocardial infarction. Male patients as well as patients with previous coronary heart disease or little regular exercise are at increased risk.

Possible additional mechanisms of exercise induced myocardial infarction are vasospasm and changes in blood clotting.

Changes in the ambient temperature (warm to cold) can also induce vasospasm which might result in reduced perfusion and plaque rupture. It seems that male patients are more involved than female patients.

Taking the exercise and the ambient temperature changes into consideration, heavy snowfall with consecutive snow shoveling is an augmented risk for acute myocardial infarction.

The rationale of the study is to test if the above mentioned constellation of environmental factors as well as potential increased exercise have a significant and independent impact on the incidence of myocardial infarctions

Inclusion Criteria:

• myocardial infarction being confirmed or treated in the cathlab

Exclusion Criteria:

• none

All patients with myocardial infarction being transfered to a cath lab either at the medical university of Graz or the department of cardiology at the state hospital Graz West