Blood pressure variability and cardiovascular autonomic control during hemodialysis in peripheral vascular disease patients.

Hemodialysis (HD) patients with peripheral vascular disease (PVD) are at higher risk of mortality. The main objectives of this work were to investigate the hypothesis of an association between the PVD and an altered control system on peripheral resistance in response to volume depletion induced by HD treatment; and to investigate whether HD induced increase of pulse pressure (PP) is associated with PVD. Continuous blood pressure (BP) was recorded during HD treatment at the beginning and at the end of HD. The overhydration condition was evaluated by means of whole body bioimpedance spectroscopy, measured before each HD treatment. BP variability, heart rate variability and baroreflex sensitivity were then analyzed. Patients affected by PVD reported a prevalence of peripheral local control as shown by higher values of very low frequency in diastolic blood pressure (DBP) variability and a reduced cardiac baroreflex with respect to patients not affected by this pathology. HD treatment induced a significant increase of PP and LF% in DBP series in PVD patients only. Our results suggested that differences in BP variability and PP changes could be related not only to an underlying vascular disease, but also to an alteration in autonomic control.