The aim is the studying of the significance of the heart rate variability (HRV) characteristics during the interpretation of the veloergometric (VEM)tests results in patients with ischemic heart disease. 243 patients with the stable angina of the II-III functional class (49 ± 8 years) were involved in the studying. The evidence of coronary pathology was assessed with the help of selective coronary angiography. Results of VEM testing, Doppler echocardiography and spectral analysis of HRV were analyzed. Registration of R-R chains was performed during 3 min in the relaxed condition and in 90 sec after the beginning of 25 Watt stage of the VEM test. Frequency assessments of HRV were obtained with the help of the parametric method of spectrum construction. The results showed, that using of the HRV spectrum indices allows to raise the diagnostic reliability of VEM tests. Negative result of a VEM trial is characterized by the low level of reliability and cannot be used as an index of absence of the coronary channel damage.
Folia Cardiologica, 2005; Vol.12, Suppl. D: p 52-55

In accordance with the concepts of autonomic heart control system functioning listed above, it provoked an direct interest, in particular, to studying of a dynamic of 0,1 Hz oscillations of the HRV in subjects with different EF of the left ventricle. The aim of the present study was investigation of dynamic stability of 0,1 Hz component of the HRV spectrum in patients with coronary artery disease (CAD) and different EF during veloergometric tests under controlled breathing with 10 seconds period. Methods: 45 male patients with CAD aged of 50±3 years with left ventricle EF<50% and 35 male patients with CAD aged of 52±6 years with left ventricle EF>60% were involved in the study. Veloergometric test was performed. Registration of R-R intervals was performed in relaxed probationer’s condition (sedentary posture) and in 90 seconds after the beginning of 25 Wt load stage of veloergometric test. The duration of R-R chain registration was 5 minutes. Frequency assessments of HRV obtained with the help of R-R chain spectrum construction on the basis of autoregressive model. Results: In process of studying of 0,1 Hz component of the HRV spectrum absence of any reliable differences in its spectral power in patients with normal and damaged EF was shown (Table 1 [Tab. 1]). Under the load rising till 25 Wt in subjects with EF<50% consequent depression of 0,1 Hz component spectral power in 2-3 times in comparison with the relaxed condition was observed (table). At the same time, there was no similar reliable expressed dynamic in the group with EF>60%. It possible to say that the activity level of the 0,1 Hz oscillations in the autonomic heart control system in subjects with EF>60% is characterized by relative tolerance to low-intensive loads, while in patients with EF<50% the activity of 0,1 Hz oscillations is very unstable to the same loads. Conclusions: The stability of 0,1 Hz component of the HRV spectrum to low intensity loads associates with the severity of myocardial contractility damage. The power dynamic of 0,1 Hz component of the HRV spectrum may be considered an independent index of dynamic stability of the heart autonomic control.
Abstract book of 33rd International Congress on Electrocardiology, Cologne, Germany, June 28th - July 1st, 2006; PS88: p 36