Pc1 geomagnetic pulsations as a potential hazard of the myocardial infarction

The analysis of 85,800 events (1979–1981) of Moscow ambulance calls, related to the myocardial infarction (MI), demonstrates a seasonal variation with the profound summer minima and winter maxima. Similar results were obtained by analyzing the 25-year (1970–1995) statistical monthly data on the death from infarction in Bulgaria. The estimated high correlation coefficient (0.84) between Moscow and Bulgarian data suggests a common reason. There is a great number of clinical and statistical studies confirming that the MI number rises during geomagnetic disturbances, which have a maximum of occurrence near equinox, not in winter. In order to explain this contradiction we suggest that one of the critical additional factors, which affect a human cardiovascular system, could be geomagnetic Pc1 pulsations at frequencies comparable with the human heart beat rate. The MI variations as well as the Pc1 pulsations exhibit a summer minimum. The comparative analysis of the Moscow ambulance MI data and Pc1 pulsations recorded at the geophysical observatory in Borok is presented. It is shown that in about 70% of the days when an anomalously great number of ambulance calls (AMI) has been registered Pc1 pulsations have been recorded. In the winter season the probability of the simultaneous AMI and Pc1 occurrence was 1.5 times larger than their accidental coincidence. Moreover, it was found that the effects of magnetic storms and Pc1 in AMI were much higher in winter than in summer. We suggest that the seasonal variation of the production of the pineal hormone melatonin leads to a winter instability in the human organisms and increases the sensitivity of the patient to the “negative” influence of Pc1 geomagnetic pulsations in winter.