The association between solar particle events, geomagnetic storms, and hospital admissions for myocardial infarction

Eruptive activity of the Sun produces intensive fluxes of energetic particles and disturbances in geomagnetic field. It has been found that solar and geomagnetic activities affect the cardiovascular system. In this study, we investigated whether solar particle events (SPE) and geomagnetic storms (GS) affect risk of emergency hospitalization for first-time myocardial infarction (MI). The effect of environmental variables is analyzed separately for MI with and without elevation of ST segment in electrocardiogram. A case-crossover study design was used to analyze MI in 2,008 hospitalized patients at the Hospital of Kaunas University of Medicine, Lithuania, from January 1, 2004 to December 31, 2005. We evaluated the associations between SPE, GS, and daily number of emergency hospital admission for MI by Poisson regression, controlling for seasonal variation, weekdays, and meteorological factors. During days of SPE in conjunction with GS, the risk of hospital admissions for MI with ST elevation increased by 39 % (RR = 1.39; 95 % CI 1.02-1.91). Two days after SPE that going till GS, the risk of admission for MI without ST elevation increased by 54 % (RR = 1.54; 95 % CI 1.05-2.24). The major GS without increased proton flux with particle energies > 10 MeV does not increase the risk of admission for MI without ST elevation. Only GS occurred after SPE increased the risk of admission for MI without ST elevation. These findings suggest that SPE going till GS or SPE in conjunction with GS affect on cardiovascular system. The environmental factors have different effects on the risk of myocardial infarction with and without ST elevation.