Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Am J Physiol Heart Circ Physiol. 2010 Jan;298(1):H158-62. doi: 10.1152/ajpheart.00654.2009. Epub 2009 Oct 23.
In the failing myocardium a subendocardial plexus can develop. Detection of the presence or function, however, of such a plexus does not form part of the present diagnostic spectrum for heart failure. This may now change as new methods for high-resolution imaging of myocardial perfusion distribution are being developed. A severely hypertrophic heart was harvested during transplantation and analyzed for morphology of the intramural coronary arterial vasculature. The heart only had one coronary ostium, and the main branches of the coronary artery were cannulated. A fluorescent casting material was infused that was allowed to harden under physiological pressure. The entire heart was frozen and placed in a novel imaging cryomicrotome and sequentially cut in 25-microm slices. High-resolution images of each cutting plane were acquired, allowing a detailed three-dimensional reconstruction of the arterial vasculature. The epicardial layer of the free wall demonstrated a normal vasculature with penetrating branching arteries. The endocardial layer and the septum revealed a highly interconnected vascular plexus with large vessels oriented parallel to the apicobasal axis. An extensive endocardial network with collaterals was detected, forming connections between the main epicardial branches. We conclude that an outward remodeling of transmural vessels did not prevent the generation and growth of subendocardial conduit arteries. The orientation and vascular volume in the plexus provides an opportunity for detection by novel techniques of MRI contrast imaging currently developed. Knowledge of the effect on perfusion studies is required to prevent a misinterpretation of subendocardial perfusion images in heart failure.
在心衰患者的心肌中可能会出现心内膜下丛。然而，目前的心力衰竭诊断标准并未将这种丛的存在或功能纳入其中。随着用于心肌灌注分布高分辨率成像的新方法的发展，这种情况可能会发生改变。在移植过程中采集了一只严重肥大的心脏，并对其心壁内冠状动脉血管结构进行了形态学分析。这颗心脏只有一个冠状动脉口，冠状动脉的主要分支都被插管了。随后，将一种荧光铸型材料注入其中，在生理压力下使其变硬。整个心脏被冷冻并放入新型成像冷冻切片机中，以 25 微米的切片顺序切割。对每个切割平面进行高分辨率图像采集，允许对动脉血管进行详细的三维重建。游离壁的心外膜层显示出正常的血管，有穿透性分支动脉。心内膜层和间隔层显示出高度相互连接的血管丛，大血管平行于心尖基底轴排列。检测到广泛的心内膜网络和侧支，它们在心外膜分支之间形成连接。我们得出结论，心壁内血管的向外重塑并未阻止心内膜下导引导管的生成和生长。丛的方向和血管体积为目前正在开发的新型 MRI 对比成像技术提供了检测机会。为了防止对心力衰竭患者心内膜下灌注图像的错误解释，需要了解其对灌注研究的影响。
