Hayashi Hideyuki, Akiyama Koichi, Itatani Keiichi, DeRoo Scott, Sanchez Joseph, Ferrari Giovanni, Colombo Paolo C, Takeda Koji, Wu Isaac Y, Kainuma Atsushi, Takayama Hiroo
Division of Cardiothoracic Surgery, Department of Surgery, Columbia University Medical Center, New York, NY, USA.
Department of Anesthesiology, Yodogawa Christian Hospital, Osaka, Japan.
Echocardiography. 2020 Feb;37(2):323-330. doi: 10.1111/echo.14596. Epub 2020 Jan 31.
Mechanical stress caused by blood flow, such as wall shear stress (WSS) and its related parameters, is key moderator of endothelial degeneration. However, an in vivo method to measure WSS on heart valves has not been developed.
We developed a novel approach, based on vector flow mapping using intraoperative epi-aortic echocardiogram, to measure WSS and oscillatory shear index (OSI) on the aortic valve. We prospectively enrolled 15 patients with normal valves, who underwent coronary artery bypass graft.
Systolic WSS on the ventricularis (2.40 ± 0.44 Pa [1.45-3.00 Pa]) was higher than systolic WSS on the fibrosa (0.33 ± 0.08 Pa [0.14-0.47 Pa], P < .001) and diastolic WSS on the ventricularis (0.18 ± 0.07 Pa [0.04-0.28 Pa], P < .001). Oscillatory shear index on the fibrosa was higher than on the ventricularis (0.29 ± 0.04 [0.24-0.36] vs 0.05 ± 0.03 [0.01-0.12], P < .001). A pilot study involving two patients with severe aortic regurgitation showed significantly different values in fluid dynamics.
Vector flow mapping method using intraoperative epi-aortic echocardiogram is an effective way of measuring WSS and OSI on normal aortic leaflet in vivo, allowing for better understanding of the pathophysiology of aortic valve diseases.
血流引起的机械应力，如壁面切应力（WSS）及其相关参数，是内皮细胞退变的关键调节因素。然而，尚未开发出一种在心脏瓣膜上测量WSS的体内方法。
我们开发了一种基于术中经主动脉超声心动图向量血流图的新方法，用于测量主动脉瓣上的WSS和振荡切变指数（OSI）。我们前瞻性纳入了15例瓣膜正常且接受冠状动脉旁路移植术的患者。
心室面的收缩期WSS（2.40±0.44 Pa [1.45 - 3.00 Pa]）高于纤维层的收缩期WSS（0.33±0.08 Pa [0.14 - 0.47 Pa]，P <.001），且心室面的舒张期WSS（0.18±0.07 Pa [0.04 - 0.28 Pa]，P <.001）也更高。纤维层的振荡切变指数高于心室面（0.29±0.04 [0.24 - 0.36] 对 0.05±0.03 [0.01 - 0.12]，P <.001）。一项涉及两名重度主动脉瓣反流患者的初步研究显示，流体动力学方面的值存在显著差异。
术中经主动脉超声心动图向量血流图方法是在体内测量正常主动脉瓣叶WSS和OSI的有效方法，有助于更好地理解主动脉瓣疾病的病理生理学。
