Verheyden Bart, Ector Hugo, Aubert Andre E, Reybrouck Tony
Division of Experimental Cardiology, University Hospital Gasthuisberg, O/N 1, bus 704, Herestraat 49, 3000 Leuven, Belgium.
Eur Heart J. 2008 Jun;29(12):1523-30. doi: 10.1093/eurheartj/ehn134. Epub 2008 Mar 27.
Tilt training is a useful therapeutic option in neurally mediated syncope (NMS). We tested the hypothesis that tilt training will restore orthostatic tolerance by increasing the degree of vasomotor reserve during sustained orthostatic stress. METHODS AND RESULTS In this follow-up study we enrolled 17 patients (age 31 +/- 22 years, 11 females) with a clinical diagnosis of NMS and two consecutive positive tilt tests. The head-up tilt test was repeated day after day: one session per day. All patients were instructed to continue a programme of daily standing training at home. Follow-up tilt testing was performed after a period of 6 weeks in 14 patients. ECG and finger arterial blood pressure (Portapres) were recorded during subsequent tilt testing. Left ventricular stroke volume (SV), cardiac output, and systemic vascular resistance were computed from the pressure pulsations (Modelflow). Spontaneous cardiac baroreflex sensitivity was estimated by cross-spectral analysis of heart rate (HR) and systolic blood pressure. In all patients, orthostatic tolerance was restored after 4.1 +/- 0.9 tilt sessions, median 4. The follow-up tilt test was also negative in all patients. This was accompanied by a significant rise in systemic vascular resistance to compensate for a postural reduction in SV in the sustained head-up tilt position. No evidence could be provided of altered baroreflex control of HR after tilt training.
Tilt training restores orthostatic tolerance at least in part by increasing the amount of vasoconstriction that can ultimately be made available during sustained orthostatic stress. The increased vasoconstrictor reserve is preserved after 6 weeks of continued standing training at home.
倾斜训练是神经介导性晕厥（NMS）的一种有效治疗选择。我们检验了这样一个假设，即倾斜训练将通过在持续性直立应激期间增加血管运动储备程度来恢复直立耐受性。
在这项随访研究中，我们纳入了17例临床诊断为NMS且连续两次倾斜试验阳性的患者（年龄31±22岁，11例女性）。每天重复进行头高位倾斜试验：每天一次。所有患者均被指导在家中继续进行每日站立训练计划。14例患者在6周后进行了随访倾斜试验。在随后的倾斜试验期间记录心电图和手指动脉血压（Portapres）。根据压力搏动（Modelflow）计算左心室每搏输出量（SV）、心输出量和全身血管阻力。通过心率（HR）和收缩压的交叉谱分析估计自发性心脏压力反射敏感性。所有患者在4.1±0.9次倾斜训练后（中位数为4次）恢复了直立耐受性。所有患者的随访倾斜试验也均为阴性。这伴随着全身血管阻力显著升高，以补偿在持续头高位倾斜位时SV的体位性降低。倾斜训练后未发现心脏压力反射对HR的控制有改变的证据。
倾斜训练至少部分通过增加在持续性直立应激期间最终可利用血管收缩量来恢复直立耐受性。在家中持续站立训练6周后，增加的血管收缩储备得以保留。
