Cardiovascular Autonomic Dysfunctions in Diabetic Polyneuropathy

Objective: To study the cardiovascular autonomic dysfunctions in diabetic polineuropathy. Material and methods: The study included 22 patients (15 women, 7 men, mean age 55,52 +/- 13,75 years) with diabetic polyneuropathy and 22 healthy subjects. The cardiovas. cular autonomic dysfunctions were estimated as heart rate responses to different stimuli: deep breathing, the Valsalva manoeuvre and active standing. The R-R intervals were recorded by means of MP100 computerizes system with ECG module. Detection of R - peaks and measurement of R-R intervals, visualization and resampling of the acquired spectrogram and calculation of the parameters in time domain and power spectral data were performed by our software, using fast Fourier transformation. Mean R-R intervals, mean heart rate, mean standard deviation of R-R intervals, low and high frequency power, low/high frequency ratio and total power were analyzed..he spectral data were compared with the maximal - minimal interval during deep breathing (R-Rmax-min), the Valsalva ratio (VR), the 30: 15 ratio and the changes of systolic, diastolic blood pressure and pulse rate after active standing, registered nonivasively. Results: The results of our study on heart rate variability in patients with diabetic polyneuropathy show reduction of the fluctuations of heart rate, lowering of the low frequency power and shorter mean R-R intervals. Abnormal cardiovascular responses with significant decrease of the R-Rmax-min response, the VR and the 30: 15 ratio in the patients in comparison to the controls was established. Discussion: The data obtained correlate with the results from the power spectral analysis of the autonomic balance and increase its sensitivity.