Heckmann J G, Hilz M J, Mück-Weymann M, Neundörfer B
Department of Neurology, University of Erlangen-Nuremberg, D-91054, Erlangen, Germany.
J Neurol Sci. 2000 Aug 1;177(1):41-7. doi: 10.1016/s0022-510x(00)00330-0.
Cerebrovascular hemodynamics during physical stress have been sparsely investigated, mostly through risky invasive techniques. The aim of this study was to determine the effect of ergometer stress on cerebrovascular hemodynamics in humans using the non-invasive and thus clinically-applicable method of transcranial Doppler sonography (TCD) combined with simultaneous non-invasive measurements of cardiovascular parameters. In eighteen healthy subjects (six women, twelve men; 29.3+/-4.6 years old) left midcerebral artery blood flow velocities (CBFVs) were continuously monitored using TCD during 3 min at rest, 3 min during ergometry and 3 min recovery. Simultaneously, systolic, diastolic, mean CBFVs, pulsatility index (PI), heart rate, beat-to-beat blood pressure (BP) and transcutaneous p(CO(2)) were measured. The subjects were supine with elevated trunk. Ergometry was performed by pedalling a Mühe-ergometer. In eight volunteers, the procedure was repeated within the next day to test the repeatability of the results. Heart rate increased significantly during ergometry (from 65.2+/-11 to 105. 3+/-12.3/min; P<0.05). The systolic BP increased significantly slightly later during ergometry (from 118.9+/-8.6 to 141.6+17.9 mmHg; P<0.05). Transcutaneous p(CO(2)) was initially within physiological ranges, but increased significantly after a delay during the 3rd min of cycling (from 39.7+/-3.7 to 41.1+/-4.7 mmHg; P<0.05). MFV started to rise significantly after 1 min of the exercise period (from 59.6+10.9 to 68.3+13.9 cm/s; P<0.05). PI increased immediately and significantly at the start of exercise (PI at rest 0.93+0.11; PI ergometry 1.1+0.13; P<0.05). The results were found to be reproducible in the eight volunteers. The cerebrovascular changes during ergometer exercise may reflect the combined activation of the cerebrovascular autoregulative mechanisms (neurogenic, myogenic and metabolic). The TCD-ergometer test presented here is non-invasive and would seem to present a low risk for patients who are judged fit enough for mild exercise. The test may contribute to the detection of cerebrovascular abnormalities in various diseases.
在身体应激期间的脑血管血流动力学方面的研究一直较少，主要是通过有风险的侵入性技术进行的。本研究的目的是使用无创且临床适用的经颅多普勒超声检查（TCD）方法，并同时对心血管参数进行无创测量，来确定测力计应激对人体脑血管血流动力学的影响。在18名健康受试者（6名女性，12名男性；年龄29.3±4.6岁）中，在静息3分钟、测力计运动3分钟和恢复3分钟期间，使用TCD连续监测左大脑中动脉血流速度（CBFV）。同时，测量收缩期、舒张期、平均CBFV、搏动指数（PI）、心率、逐搏血压（BP）和经皮二氧化碳分压（p(CO₂)）。受试者仰卧，躯干抬高。通过蹬踏Mühe测力计进行测力计运动。在8名志愿者中，第二天重复该过程以测试结果的可重复性。在测力计运动期间心率显著增加（从65.2±11次/分钟增加到105.3±12.3次/分钟；P<0.05）。收缩压在测力计运动稍晚时显著升高（从118.9±8.6 mmHg增加到141.6±17.9 mmHg；P<0.05）。经皮二氧化碳分压最初在生理范围内，但在骑行第3分钟延迟后显著增加（从39.7±3.7 mmHg增加到41.1±4.7 mmHg；P<0.05）。运动期开始1分钟后MFV开始显著上升（从59.6±10.9 cm/s增加到68.3±13.9 cm/s；P<0.05）。PI在运动开始时立即显著增加（静息时PI为0.93±0.11；测力计运动时PI为1.1±0.13；P<0.05）。在8名志愿者中发现结果具有可重复性。测力计运动期间的脑血管变化可能反映了脑血管自动调节机制（神经源性、肌源性和代谢性）的联合激活。这里介绍的TCD-测力计测试是无创的，对于被判定适合轻度运动的患者似乎风险较低。该测试可能有助于检测各种疾病中的脑血管异常。
