[Biorthythmological risk factors for progression of coronary heart disease].

The study was undertaken to study a role of periods of an individual annual cycle (IAC) (from the date of a birthday to the following one) and the season of a year in patients with coronary heart disease (CHD) in its progression. The study enrolled 52 patients with functional classes II and stable angina pectoris. Clinical and functional parameters were estimated by the data of bicycle ergometric test (BET), 24-hour monitoring (24-h M), ECG, and echocardiography. The vast majority of cases of progression of angina were observed in autumn and winter. Moreover, in patients with angina, the duration of silent ischemia significantly increased and heart rate variability decreased in winter and that of painful ischemia increased in autumn, as evidenced by 24-h M. Trimesters 1 (months 1 to 3 from the date of birth) and particularly IV (months 10 to 12 from the date of birth) have been found to be characterized by a poor course of CHD. Thus, in trimester IV, the duration of total, and silent ischemia significantly prolonged, as shown by 24-h M; episodes of latent coronary insufficiency increased in number, as evidenced by BET. Thus, the course of CHD is determined by a number of biorhythmological factors: the season of a year and the period of IAC.