Heliogeophysical activity and mortality from acute myocardial infarction: results of studies based on data from Bulgaria and Azerbaijan

In this paper we partly describe the results of the joint studies to reveal possible effects of geomagnetic disturbances varying in strength and type on the lethality from acute myocardial infarction (AMI). The AMI mortality data were taken from "St. Anna" University Hospital for Active Treatment, Sofia, Bulgaria (109 consecutive months 01.12.1995 through 31.12.2004, covering 175 AMI cases in hospital) and from all of Emergency and First Medical Aid Stations of Grand Baku Area, Azerbaijan (36 months daily pre-hospital data 01.01.2003 through 31.12.2005, covering 440 cases). Analysis of variance (ANOVA) was applied to check the significance of the influence of different geomagnetic activity (GMA) indices (Ap, Am, Kpand Dst) on the dynamics of lethal cases. The same analysis was applied to study the effect of the geomagnetic storm types (i.e., those caused by solar origin magnetic clouds (MC) or by high-speed solar wind streams (HSSWS)) on AMI mortality. We also used correlation analysis and calculated relevant coefficients. The AMI mortality in both regions increased with GMA increase a day prior to, during and the day after geomagnetic storms of different intensity. The number of lethal AMIs also increased on the days with low GMA 2003 through 2004. For the entire considered period, we show the relation between the MC-caused geomagnetic storms and increase of AMI mortality both in Sofia and Baku as compared with the HSSWS-caused storms.