Although orthostatic hypotension is more prominent in multiple system atrophy (MSA) than in Parkinson’s disease (PD), there is no study comparing the degree of decrease in total peripheral resistance and cardiac response during orthostatic stress between both diseases. In this study, we examined whether there is a difference in cardiovascular response between MSA and PD. We examined the results of the head-up tilt test in 68 patients with MSA, 28 patients with cardiac non-denervated PD, and 70 patients with cardiac denervated PD whose total peripheral resistance after 60° tilting was lower than the value at 0°. Differences in cardiac output and blood pressure changes were compared against the decrease in total peripheral resistance. There was no difference in the degree of decrease in total peripheral resistance among the three groups. However, the slope of the regression line revealed that the increase in cardiac output against the change in total peripheral resistance was significantly lower in the MSA group than in the cardiac non-denervated and denervated PD groups, and that the decrease in systolic blood pressure against the change in total peripheral resistance was significantly greater in the MSA group than in the cardiac non-denervated and denervated PD groups. In MSA, the cardiac response during orthostatic stress is lower than that in PD, possibly underlying the fact that orthostatic hypotension is more prominent in MSA than in PD.

尽管直立性低血压在多系统萎缩 (MSA) 中比在帕金森病 (PD) 中更为突出，但没有研究比较两种疾病在直立性应激期间总外周阻力和心脏反应的降低程度。在这项研究中，我们检查了 MSA 和 PD 之间的心血管反应是否存在差异。我们检查了 68 名 MSA 患者、28 名心脏非去神经支配性 PD 患者和 70 名心脏去神经支配性 PD 患者（60°倾斜后总外周阻力低于 0°时的值）的平视倾斜试验结果。将心输出量和血压变化的差异与总外周阻力的降低进行比较。三组间总外周阻力降低程度无差异。然而，回归线的斜率显示，MSA 组心输出量增加对总外周阻力变化的影响显着低于心脏非去神经和去神经 PD 组，收缩压的降低对总外周阻力的变化MSA 组的总外周阻力显着高于心脏非去神经和去神经 PD 组。在 MSA 中，直立性应激期间的心脏反应低于 PD，这可能是 MSA 中直立性低血压比 PD 更突出的原因。并且 MSA 组收缩压随总外周阻力变化的降低显着大于心脏非去神经和去神经 PD 组。在 MSA 中，直立性应激期间的心脏反应低于 PD，这可能是 MSA 中直立性低血压比 PD 更突出的原因。并且 MSA 组收缩压随总外周阻力变化的降低显着大于心脏非去神经和去神经 PD 组。在 MSA 中，直立性应激期间的心脏反应低于 PD，这可能是 MSA 中直立性低血压比 PD 更突出的原因。