Mechanical and Aerospace Engineering Department, University of California, San Diego, La Jolla, California.
Department of Cardiology, Hospital General Universitario Gregorio Marañón, Facultad de Medicina, Universidad Complutense de Madrid, and the Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
J Am Coll Cardiol. 2014 Oct 21;64(16):1711-21. doi: 10.1016/j.jacc.2014.06.1205.
Intraventricular fluid dynamics can be assessed clinically using imaging. The contribution of vortex structures to left ventricular (LV) diastolic function has never been quantified in vivo.
This study sought to understand the impact of intraventricular flow patterns on filling and to assess whether impaired fluid dynamics may be a source of diastolic dysfunction.
Two-dimensional flow velocity fields from color Doppler echocardiographic sequences were obtained in 20 patients with nonischemic dilated cardiomyopathy (NIDCM), 20 patients with hypertrophic cardiomyopathy (HCM), and 20 control healthy volunteers. Using a flow decomposition method, we isolated the rotational velocity generated by the vortex ring from the surrounding flow in the left ventricle.
The vortex was responsible for entering 13 ± 6% of filling volume in the control group and 19 ± 8% in the NIDCM group (p = 0.004), but only 5 ± 5% in the HCM group (p < 0.0001 vs. controls). Favorable vortical effects on intraventricular pressure gradients were observed in the control and NIDCM groups but not in HCM patients. Differences in chamber sphericity explained variations in the vortex contribution to filling between groups (p < 0.005).
The diastolic vortex is responsible for entering a significant fraction of LV filling volume at no energetic or pressure cost. Thus, intraventricular fluid mechanics are an important determinant of global chamber LV operative stiffness. Reduced stiffness in NIDCM is partially related to enhanced vorticity. Conversely, impaired vortex generation is an unreported mechanism of diastolic dysfunction in HCM and probably other causes of concentric remodeling.
可以通过影像学评估脑室内的流体动力学。涡旋结构对左心室（LV）舒张功能的贡献从未在体内进行过定量评估。
本研究旨在了解心室内流动模式对充盈的影响，并评估流体动力学的受损是否可能是舒张功能障碍的一个来源。
对 20 例非缺血性扩张型心肌病（NIDCM）患者、20 例肥厚型心肌病（HCM）患者和 20 例健康志愿者进行二维血流速度场彩色多普勒超声心动图序列检查。使用流分解方法，我们从左心室周围的血流中分离出涡环产生的旋转速度。
在对照组中，涡旋负责进入 13±6%的充盈量，在 NIDCM 组中为 19±8%（p=0.004），但在 HCM 组中仅为 5±5%（p<0.0001 与对照组相比）。在对照组和 NIDCM 组中观察到涡旋对心室内压力梯度有有利影响，但在 HCM 患者中没有。心室球度的差异解释了各组之间涡旋对充盈贡献的变化（p<0.005）。
舒张期涡旋负责进入左心室充盈量的重要部分，而不会增加能量或压力成本。因此，心室内流体力学是整体心室 LV 操作刚度的一个重要决定因素。NIDCM 中的刚度降低部分与增强的涡度有关。相反，涡旋生成受损是 HCM 以及其他原因的同心性重构中舒张功能障碍的一种未被报道的机制。
