Department of Pulmonary Diseases, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, Amsterdam, The Netherlands.
J Appl Physiol (1985). 2012 Oct 15;113(8):1285-91. doi: 10.1152/japplphysiol.00432.2012. Epub 2012 Aug 30.
Arterial compliance is mainly determined by the elasticity of proximal large-conduit arteries of which the aorta is the largest contributor. Compliance forms an important part of the cardiac load and plays a role in organ (especially coronary) perfusion. To follow local changes in aortic compliance, as in aging, noninvasive determination of compliance distribution would be of great value. Our goal is to determine regional aortic compliance noninvasively in the human. In seven healthy individuals at six locations, aortic blood flow and systolic/diastolic area (ΔA) was measured with MRI. Simultaneously brachial pulse pressure (ΔP) was measured with standard cuff. With a transfer function we derived ΔP at the same aortic locations as the MRI measurements. Regional aortic compliance was calculated with two approaches, the pulse pressure method, and local area compliance (ΔA/ΔP) times segment length, called area compliance method. For comparison, pulse wave velocity (PWV) from local flows at two locations was determined, and compliance was derived from PWV. Both approaches show that compliance is largest in the proximal aorta and decreases toward the distal aorta. Similar results were found with PWV-derived compliance. Of total arterial compliance, ascending to distal arch (segments 1-3) contributes 40% (of which 15% is in head and arms), descending aorta (segments 4 and 5) 25%, and "hip, pelvic and leg arteries" 20%. Pulse pressure method includes compliance of side branches and is therefore larger than the area compliance method. Regional aortic compliance can be obtained noninvasively. Therefore, this technique allows following changes in local compliance with age and cardiovascular diseases.
动脉顺应性主要由近端大血管的弹性决定，其中主动脉的贡献最大。顺应性是心脏负荷的重要组成部分，在器官（尤其是冠状动脉）灌注中发挥作用。为了跟踪主动脉顺应性的局部变化，如在衰老过程中的变化，无创性确定顺应性分布将具有重要价值。我们的目标是在人体中无创地确定区域性主动脉顺应性。在七名健康个体的六个位置，使用 MRI 测量了主动脉血流和收缩/舒张面积（ΔA）。同时，使用标准袖带测量了肱动脉脉搏压（ΔP）。通过传递函数，我们在与 MRI 测量相同的主动脉位置上推导出了ΔP。使用两种方法计算了区域性主动脉顺应性，即脉搏压法和局部面积顺应性（ΔA/ΔP）乘以节段长度的面积顺应性法。为了比较，从两个位置的局部流量确定了脉搏波速度（PWV），并从 PWV 推导出顺应性。两种方法都表明，顺应性在近端主动脉最大，并向远端主动脉逐渐减小。从 PWV 推导的顺应性也得出了相似的结果。总动脉顺应性中，升主动脉至远端弓（节段 1-3）占 40%（其中 15%位于头部和手臂），降主动脉（节段 4 和 5）占 25%，“臀部、骨盆和腿部动脉”占 20%。脉搏压法包括侧支的顺应性，因此大于面积顺应性法。可以无创地获得区域性主动脉顺应性。因此，这种技术允许随着年龄和心血管疾病的变化跟踪局部顺应性的变化。
