[Effect of premedication in general anesthesia on periodic variability of heart rate]. 
During the premedication phase the temporary course of the sinus arrhythmia was studied on 10 patients without cardiocirculatory diseases undergoing insufflation anaesthesia.  The progress of heart rate variability was observed in periodic components by calculation of power density spectra.  The results reveal a significant decrease of the spontaneous variations of the heart rate after 40 to 50 minutes action of atropine and pethidine.  Periodic components of respiration and circulation are more reduced than long wave spectral ranges.  Their residue is a measure for the size of the inhibition of the vagal impulse.  The inverse atropine effect is preponderantly to be observed in periodic components of respiration and circulation.  About 30 minutes after the injection of the premedication mixture a new steady state was found concerning the circulatory and respiratory rhythm.