Gutron treatment of patients suffering from essential orthostatic hypotony. Part Two--Autonomic system investigation.
Neurovegative control of circulatory system in essential orthostatic hypotony (EOH) is not well recognized. Therefore, in group of 9 patients (pts) with EOH treated with midodrine (Gutron, Gu) 5 mg i.v. we performed a study of sympathovagal balance, based on heart rate variability (HRV) analysis. From computer-assisted tachograms we calculated standard deviation of 512 sinus cycles length (SD-SCL) and from power spectral analysis by fast Fourier transformation we derived: amplitudes of high frequency (HF, 0.15-0.35 Hz) and low frequency (LF, 0.05-0.15 Hz) spectra, percentage of power of HF and LF spectra and their ratio, named vegetative control coefficient (VCC, %LF:%HF). Results were compared to that received from control group (11 volunteers). We found that EOH-pts presented lower amplitude of HF, especially after Gu, a lack of increment of %LF irrespective to treatment and higher VCC, which normalized to control value after Gu. We stated that: 1) both branches of autonomic system are disturbed in EOH-patients; 2) Gutron shifts sympatho-vagal balance from initial resting sympathicotomy into parasympathetic predominance.
Petelez
T
T
III Clinic of Cardiology, Silesian Academy of Medicine, Katowice, Poland.
Sosnowski
M
M
Axenti
I
I
D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005583:Fourier Analysis; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007024:Hypotension, Orthostatic / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008879:Midodrine / Q000627:therapeutic use*; D012815:Signal Processing, Computer-Assisted
D008879:Midodrine