Vanden Eynden Frederic, El-Oumeiri Bachar, Bové Thierry, Van Nooten Guido, Segers Patrick
Cardiac Surgery, Université Libre de Bruxelles, Hôpital Académique Erasme, Brussels , Belgium.
Laboratory of Experimental Cardiac Surgery, Ghent University Hospital , Ghent , Belgium.
Am J Physiol Heart Circ Physiol. 2019 May 1;316(5):H992-H1004. doi: 10.1152/ajpheart.00635.2018. Epub 2019 Feb 15.
Locating the site of increased resistance within the vascular tree in pulmonary arterial hypertension could assist in both patient diagnosis and tailoring treatment. Wave intensity analysis (WIA) is a wave analysis method that may be capable of localizing the major site of reflection within a vascular system. We investigated the contribution of WIA to the analysis of the pulmonary circulation in a rabbit model with animals subjected to variable occlusive pulmonary disease. Animals were embolized with different sized microspheres for 6 wk ( n = 10) or underwent pulmonary artery (PA) ligation for 6 wk ( n = 3). These animals were compared with a control group ( n = 6) and acutely embolized animals ( n = 4). WIA was performed and compared with impedance-based methods to analyze wave reflections. The control group showed a relatively high extent of reflected waves (15.7 ± 10.6%); reflections had a net effect of pressure reduction during systole, suggesting an open-end reflector. The pattern of wave reflection was not different in the group with partial PA ligation (12.4 ± 4.1%). In the chronically embolized group, wave reflection was not observed (3.6 ± 1.5%). In the acute embolization group, wave reflection was more prominent (37.3 ± 12.6%), with the appearance of a novel wave increasing pressure, suggesting the appearance of a closed-end reflector. Wave reflections of an open-end type are present in the normal rabbit pulmonary circulation. However, the pattern and nature of reflections vary according to the extent of pulmonary vascular occlusion. NEW & NOTEWORTHY The study proposes an original framework of a complementary analysis of wave reflections in the time domain and in the frequency domain. The methodology was used in the pulmonary circulation with different forms of chronic obstructions. The results suggest that the pulmonary vascular tree generates a reflection pattern that could actually assist the heart during ejection, and chronic obstruction significantly modifies the pattern.
确定肺动脉高压时血管树中阻力增加的部位有助于患者诊断和个性化治疗。波强度分析（WIA）是一种波分析方法，可能能够定位血管系统内的主要反射部位。我们在患有不同程度闭塞性肺部疾病的兔模型中研究了WIA对肺循环分析的作用。用不同大小的微球栓塞动物6周（n = 10）或进行肺动脉（PA）结扎6周（n = 3）。将这些动物与对照组（n = 6）和急性栓塞动物（n = 4）进行比较。进行WIA并与基于阻抗的方法比较以分析波反射。对照组显示出相对较高的反射波程度（15.7±10.6%）；反射在收缩期有减压的净效应，提示为开口端反射器。部分PA结扎组的波反射模式无差异（12.4±4.1%）。在慢性栓塞组中，未观察到波反射（3.6±1.5%）。在急性栓塞组中，波反射更明显（37.3±12.6%），出现了一个增加压力的新波，提示出现了封闭端反射器。正常兔肺循环中存在开口端型波反射。然而，反射的模式和性质根据肺血管闭塞的程度而变化。新内容与值得注意之处本研究提出了一个在时域和频域对波反射进行互补分析的原创框架。该方法用于不同形式慢性阻塞的肺循环。结果表明，肺血管树产生的反射模式实际上可以在心脏射血时提供帮助，而慢性阻塞会显著改变这种模式。
