Internal Medicine, Cardiology Division, The University of Texas Southwestern Medical Center, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.
Adv Exp Med Biol. 2018;1065:413-431. doi: 10.1007/978-3-319-77932-4_26.
Pregnancy is associated with significant changes in maternal hemodynamics, which are triggered by profound systemic vasodilation and mediated through the autonomic nervous system as well as the renin-angiotensin-aldosterone system. Vascular function changes to help accommodate an increase in intravascular volume due to blood volume expansion associated with pregnancy while maintaining the efficiency of ventricular-arterial coupling and diastolic perfusion pressure. The heart undergoes physiological (eccentric) hypertrophy due to increased volume load and cardiac stroke work, whereas the functional change of the left ventricle remains controversial. There are changes in cardiac electrical activity during pregnancy which can be detected in the electrocardiogram that are not related to disease. Sympathetic activation is a common phenomenon during uncomplicated pregnancy and may be a compensatory mechanism induced by profound systemic vasodilation and a decrease in mean arterial pressure. Despite marked sympathetic activation, vasoconstrictor responsiveness is blunted during uncomplicated pregnancy. There are race and ethnic differences in maternal hemodynamic adaptations to uncomplicated pregnancy, which may be attributed to differences in socioeconomic status or in prevalence rates of cardiovascular risk factors.
妊娠伴随着母体血液动力学的显著变化，这些变化是由全身血管舒张引起的，并通过自主神经系统以及肾素-血管紧张素-醛固酮系统介导。血管功能的变化有助于适应因妊娠相关的血容量增加而导致的血管内容量增加，同时保持心室-动脉偶联和舒张灌注压的效率。心脏由于容量负荷增加和心搏做功增加而发生生理性（离心性）肥大，而左心室的功能变化仍存在争议。妊娠期间心脏电活动发生变化，心电图可检测到与疾病无关的变化。妊娠期间交感神经激活是常见现象，可能是由全身血管舒张和平均动脉压降低引起的代偿机制。尽管存在明显的交感神经激活，但在正常妊娠期间血管收缩反应性减弱。在正常妊娠期间，母体血液动力学适应存在种族和民族差异，这可能归因于社会经济地位或心血管危险因素的流行率的差异。
