Meta-analyzed heart rate variability, exposure to geomagnetic storms, and the risk of ischemic heart disease.

The aim was to examine how heart rate variability (HRV) relates to the risk of ischemic heart disease (IHD) and may provide a means to assess effects of exposure to geomagnetic storms. In Stockholm, the 24-hour SD of hourly estimates of heart rate (HR) were obtained by Holter monitoring from 50 men who had had an acute myocardial infarction or had angina pectoris and compared to that of 50 clinically healthy men of similar age. In Tokyo, the HR 121 normotensives and 176 treated hypertensives was monitored. The incidence of IHD was recorded prospectively for 6 years. These results are aligned with those of a retrospective analysis of archived data on all crews of the Soyuz spacecraft for 1990-1994 focused on ECG from cosmonauts (47 male and 2 female) at times corresponding to geomagnetic storms. The results clearly indicate a decrease in HRV in association with IHD (20.5%, p=0.002 in Stockholm, 20.0%, p=0.04 in Tokyo). By comparison, the about 30% decrease (p=0.041) in rms SD of HR in cosmonauts studied during a geomagnetic storm as compared to cosmonauts monitored on quiet days adds supportive evidence to the proposition that exposure to geomagnetic disturbances increases cardiovascular disease risk.