[The origin of the biological week from data on the rhythm of cardiac contractions in people during the solar activity cycle]. / O probleme proiskhozhdeniia biologicheskoi nedeli po dannym o variatsiiakh ritma chastoty serdechnykh sokrashchenii u liudei v tsikle solnechnoi aktivnosti.

A human biologic week in the heart rate variations was compared with the variations of the sunspot area and geomagnetic activity over the solar cycle. The low ratio of amplitude of circaseptan rhythm to that of circadian rhythm in the heart rate of several clinically healthy men who did around-the-clock self-measurements in a number of years coincides with the period of anomalously low amplitude of circaseptan rhythm of the solar activity. Results herein suggest that physiologic circaseptan rhythms are built into the genome being adapted evolutionary to the original heliogeomagnetic environmental circaseptans.

Resonance of about-weekly human heart rate rhythm with solar activity change.

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.