29 巻 (1987) 10 号 p. 1249-1259
The autonomic function was evaluated in 18 hypotensives (HP), 22 normotensives (NT) and 16 hypertensives (HT) patients on longterm hemodialysis (HD) and compared with 8 with Shy-Drayger syndrome (SDS), etc. The interbeat interval response to Valsalva maneuver (Vm) was significantly lower in HP than NT (p<0 .01) or HT (p<0.001) and was similar to those of SDS (n, s.).Overshoot in arterial pressure after Vm was positive in HP 8.3%, NT 71.4%, HT 100% and SDS 0%. Among HD patients, HP showed the most serious baroreflex arc dysfunction. However, the response to cold pressor test in HD patients was as same as those of SDS and controls . Clonidine test demonstrated depressor response in HP. Although, the decrease of SBP (p<0 .01) and DBP (p<0, 02) during orthostasis was smaller in HP than SDS, no change of heart rate was observed between HP and SDS. Thus, the afferent or efferent limbs and central sympathetic activity appeared to be intact. Although the decrease of pressor response to angiotensin II independent of PRA levels in HP, the response to norepinephrine (NE) was related to plasma NE levels. Furthermore, motor nerve conduction velocity was delayed in HP in comparison with NT and HT Administration of midodrine raised SBP from 91.0±7.6 to 110.0±27.2 mmHg and DBP from 51.613.4 to 61.8±19.6 mmHg. The results suggest the abnormalities in baroreflex arc and vascular wall contractility with peripheral neuropathy. Therefore, we conclude that, although the sites remained to be clarified, HP show the autonomic disorders and that midodrine seems to be effective on such patients.