Streeten D H
Department of Medicine, SUNY Upstate Medical University, Syracuse, New York 13210, USA.
Am J Med Sci. 2001 Mar;321(3):163-7. doi: 10.1097/00000441-200103000-00001.
In patients with acute orthostatic hypotension, there is excessive pooling of blood in the legs, which may result from the strikingly subnormal compliance that is demonstrable in the pedal veins during norepinephrine infusion. The common occurrence of delayed orthostatic hypotension and/or tachycardia in the chronic fatigue syndrome (CFS) led to the present studies of foot vein compliance in CFS patients with a linear variable differential transformer.
Seven patients with CFS were compared with 7 age- and gender matched healthy control subjects in their blood pressure, heart-rate, and plasma norepinephrine responses to prolonged standing and in measurements of their foot vein contractile responses to intravenous norepinephrine infusions with the linear variable differential transformer.
Excessive, delayed (usually after 10 min) orthostatic reductions in systolic and diastolic blood pressure (P < 0.01) and inconsistently excessive increases in heart rate were found in the CFS patients, in whom venous compliance in response to infused norepinephrine was significantly reduced (P < 0.05).
In these patients with CFS, delayed orthostatic hypotension was clearly demonstrable, and, as in previously reported patients with orthostatic hypotension of acute onset, this was associated with reduced pedal vein compliance during norepinephrine infusion, implying impaired sympathetic innervation of foot veins. The rapid symptomatic improvement demonstrated in previous studies of CFS patients during correction of orthostatic venous pooling by inflation of military antishock trousers (MAST) to 35 mm Hg may suggest that excessive lower body venous pooling, perhaps by reducing cerebral perfusion, is involved in the orthostatic component of fatigue in these patients.
在急性体位性低血压患者中，腿部会出现过多的血液淤积，这可能是由于在输注去甲肾上腺素期间足静脉中明显低于正常的顺应性所致。慢性疲劳综合征（CFS）中延迟性体位性低血压和/或心动过速的常见发生导致了目前使用线性可变差动变压器对CFS患者足静脉顺应性的研究。
将7例CFS患者与7例年龄和性别匹配的健康对照者进行比较，观察他们在长时间站立时的血压、心率和血浆去甲肾上腺素反应，以及使用线性可变差动变压器测量他们对静脉输注去甲肾上腺素的足静脉收缩反应。
CFS患者出现过度、延迟（通常在10分钟后）的收缩压和舒张压体位性降低（P<0.01），心率增加不一致且过度，这些患者对输注去甲肾上腺素的静脉顺应性显著降低（P<0.05）。
在这些CFS患者中，延迟性体位性低血压明显可见，并且与先前报道的急性发作体位性低血压患者一样，这与输注去甲肾上腺素期间足静脉顺应性降低有关，意味着足静脉的交感神经支配受损。先前对CFS患者的研究表明，通过将军事抗休克裤（MAST）充气至35mmHg来纠正体位性静脉淤积时，症状迅速改善，这可能表明过多的下半身静脉淤积，可能通过减少脑灌注，参与了这些患者疲劳的体位性成分。
