[Circadian index as indicator of stable organization of heart circadian rhythm].

The author proposes to use circadian index (CI) as a method of evaluation of major structure of the circadian heart rhythm profile in Holter monitoring. CI is calculated as a ratio of awaking (7 a.m. to 22 p.m.) mean heart rate to sleep (23 p.m. to 6 a.m.) mean heart rate. CI was estimated by the literature data on 7648 healthy subjects and patients aged 2 to 79 years. In healthy subjects CI was stable irrespective of the sex and age. Normal CI makes up 1.33 +/- 0.05. All the cardiovascular patients exhibited increasing rigidity of the rhythm with the disease progression and deterioration of the prognosis. In patients with diabetes mellitus with vegetopathy rigidity of the circadian rhythm grows with aggravation of vegetopathy. In neurological patients free of vegetopathy CI was normal. Intensification of the heart rhythm profile was seen in patients with high sensitivity to catecholamines.