[Heart rate variability and blood pressure variability in patients with heart failure undergoing cardiac rehabilitation].

BACKGROUND

Autonomic nervous system plays an important role in the pathogenesis of chronic heart failure (CHF). Increasing sympathetic nervous activity and decreasing parasymphatetic activity has been observed in the course of CHF. Physical training modulates the activity of the autonomic nervous system and restores the sympathovagal balance, hence it may improve the prognosis in CHF.

AIM

The aim of the study was to assess the influence of a 6-month physical training in patients with chronic ischaemic heart failure on the indices of autonomic nervous system activity--blood pressure and heart rate variability.

METHODS

The study group consisted of 42 patients with CHF, NYHA class II and III. Patients were divided into three groups: Group I--patients who were not trained at all, Group II--patients with interval training, Group III--patients who were trained according to model with progressive increase of workload. At baseline groups did not differ according to age, clinical parameters and biochemical parameters. In all subjects 24-hr ECG monitoring was performed (with time domain heart rate variability assessment), as well as 24-hr blood pressure monitoring to analyse blood pressure variability.

RESULTS

After 6 months we observed significant improvement in HRV parameters in Group III--those trained with progressive increase of workload (delta SDNN + 88.2 ms, p < 0.05). In Group II (interval training) HRV parameters remained unchanged after 6 months of training (delta SDNN + 2.5 ms, NS). Group I (without training) revealed deterioration in HRV parameters (delta SDNN--12.9 ms, p < 0.05). There were no differences in the mean blood pressure and blood pressure variability in all examined groups after 6 months of follow-up compared to baseline.

CONCLUSION

In the examined group of patients with chronic heart failure, 6 months physical training with progressive increase of workload significantly improves autonomic function assessed by means of heart rate variability.