Cariga P, Mathias C J
Neurovascular Medicine Unit, Imperial College School of Medicine at St. Mary's Hospital, Praed Street, London W2 1NY, U.K.
Clin Sci (Lond). 2001 Sep;101(3):313-9.
Oral water ingestion increases blood pressure in normal elderly subjects and in patients suffering from autonomic failure, but the time course of the haemodynamic changes is not known. We therefore studied 14 subjects with documented sympathetic denervation due to pure autonomic failure, with continuous haemodynamic recordings obtained before and after ingestion of 500 ml of distilled water at room temperature. The time course of changes in values of systolic and diastolic beat-by-beat finger blood pressure, heart rate, stroke volume, cardiac output, ejection fraction and total peripheral resistance were analysed. Systolic blood pressure rose from 115+/-8 mmHg (mean+/-S.E.M.) to 133+/-8 mmHg (P<0.001), and diastolic blood pressure from 64+/-4 to 73+/-4 mmHg (P<0.001), with the pressor response beginning a few minutes after water ingestion, plateauing between 10 and 35 min (peak at 14 min), and returning to baseline at 50 min. Heart rate fell from 71+/-2.5 to 67+/-2 beats/min (P<0.001), and total peripheral resistance increased from 1.31+/-0.19 to 1.61+/-0.24 m-units (P<0.001). There were no significant changes in ejection fraction, stroke volume or cardiac output. This study confirmed a pressor response to oral water in subjects with sympathetic denervation. The temporal profile of the response did not favour reflexly mediated sympathetic activation. As subjects with autonomic failure are prone to salt and water depletion, and since blood pressure is exquisitely sensitive to such changes, it may be that the observed response is due to repletion or restoration of intravascular and extravascular fluid volume.
正常老年人和自主神经功能衰竭患者口服水会使血压升高，但血流动力学变化的时间过程尚不清楚。因此，我们研究了14例因单纯自主神经功能衰竭而有交感神经去神经支配记录的受试者，在室温下摄入500毫升蒸馏水前后进行连续血流动力学记录。分析了逐搏测量的收缩压和舒张压、心率、每搏输出量、心输出量、射血分数和总外周阻力值的变化时间过程。收缩压从115±8 mmHg（平均值±标准误）升至133±8 mmHg（P<0.001），舒张压从64±4 mmHg升至73±4 mmHg（P<0.001），升压反应在饮水后几分钟开始，在10至35分钟之间达到平稳（14分钟时达到峰值），并在50分钟时恢复到基线水平。心率从71±2.5次/分钟降至67±2次/分钟（P<0.001），总外周阻力从1.31±0.19 m单位增加至1.61±0.24 m单位（P<0.001）。射血分数、每搏输出量或心输出量无显著变化。本研究证实了交感神经去神经支配受试者对口服水的升压反应。该反应的时间特征不支持反射介导的交感神经激活。由于自主神经功能衰竭患者容易出现盐和水缺乏，且血压对这种变化极为敏感，因此观察到的反应可能是由于血管内和血管外液体量的补充或恢复。
