The data of this study were obtained by 86 volunteers (33 male, 56 female, average age of 47.8 +/- 11.9 years, 26 of them were undergoing cardiovascular drug treatment). Data were recorded between 1st of october 2001 to 9th of November 2001 and 8th of april 2002 to 28th may 2002 in Sofia/Bulgaria (i.e. middle latitudes). The time periods were chosen due to the expected high probability for solar activity and changes in the geomagnetic field (35-320 nT, which were recorded by the Bulgarian Geomagnetic Observatory).
Arterial, systolic and diastolic blood pressure were found to be significantly increased during increased geomagnetic activity. No significanlty effects on heart rate could be found.