Study of heart rate and blood pressure variability during the haemodialysis treatment

Analysis of variability series obtained from synchronous recordings of ECG and arterial blood pressure (ABP) signals has been applied to 9 patients during haemodialitic treatment. Information about the activity of neural systems controlling the heart has been extracted through autoregressive spectral analysis and estimation of time domain parameters. Hypotension prone (unstable) patients show values of LF/HF ratio, which measures the sympathovagal balance, always lower than hypotension resistant (stables) ones. Results suggest an interpretative hypothesis for which the reduced response of the baroreceptive mechanism in unstable patients could be responsible for the hypotensive crises.