Dynamic analysis of heart rate variability from 7-day Holter recordings associated with geomagnetic activity in subarctic area

Any influence of the natural variation in the geomagnetic field on human health has become an increasingly pertinent question in view of associations in space with myocardial infarction and stroke in Israel, Mexico, Minneapolis and Russia. HRV is examined on the basis of 7-day records by Holter ECG on 14 clinically healthy subjects (21-54 years) in Alta, Norway. Cross-spectra between geomagnetic activity and HRV measures were quantified via the squared coherence spectrum. Coherence was observed at the circadian frequency in VLF (coherence value: 0.6895), LF (0.6667) and HF (0.7065). Circadian coherence between geomagnetic disturbance and HRV endpoints would prompt the hypothesis that in polar regions human circadian periodicity is coordinated not only by photic factors, but also by non-photic circadian geomagnetic disturbance.