[Heart rate variability in the prognosis of tilt-testing results]

Study aim was assessment of dynamics of spectral parameters of heart rate variability (HRV) during the Westminster and Italian protocols of tilt-test (TT). We included in this study 114 patients with recurrent vasovagal syncope (VVS). Basing on TT results we distinguished 4 groups of patients: with positive result of the Westminster protocol (WPTT) (group 1, n=30); with negative result of WPTT (group 2, n=23); with positive result of the Italian protocol (IPTT) (group 3, n=44); with negative result of IPTT (group 4, n=11). Control group comprised 14 healthy persons without history of syncope. Spectral parameters of HRV were analyzed in 3 five minutes intervals (before TT in horizontal position, during first and last 5 minutes of orthostasis). Structure of vasovagal responses was similar for all TT protocols used. In lying position in patients of groups 1-3 lower values of LF1 and LF1/HF1 were registered, as well as high values of HF1 compared with the control group and patients with negative results of IPTT. Initial stage of TT in patients with positive result of WPTT (group 1) was characterized by almost twofold increase of LF values (n.u.) and decrease of HF parameters (n.u.) compared with other patients. In the group 1 during the second period.