Department of Cardiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
J Thorac Cardiovasc Surg. 2010 Jun;139(6):1501-10. doi: 10.1016/j.jtcvs.2009.07.060. Epub 2010 Apr 2.
Echocardiographic particle image velocimetry is a new feature tracking-based approach to visualize and quantify left ventricular flow patterns in vivo. We investigated the potential role of this new technique by assessing vortex formations in healthy left ventricles and the effect of different types of prosthetic valves on intraventricular flow patterns and flow-mediated energy dissipation.
We examined 19 patients (mean age, 57 +/- 19 years; 10 women). Nine were healthy, and 10 had prosthetic mitral valves (5 had bileaflet valves, 4 had bioprostheses, and 1 had a tilting-disc valve). Boluses of left heart contrast were administered intravenously. Echocardiographic apical views were analyzed offline by using prototype software that allowed intracavitary flow to be explored and enabled calculations of energy dissipation (relative pulsatile vorticity strength and vortex pulsation correlation) by means of particle image velocimetry.
In healthy hearts a vortex filling the entire ventricle stores the kinetic energy of the blood and smoothly redirects the blood to the outflow tract. In patients with prosthetic valves, completely different flow patterns were identified depending on the type, orientation, and position of the valves, as well as left ventricular geometry. Patients with prosthetic valves showed significantly higher left ventricular energy dissipation than healthy subjects (relative pulsatile vorticity strength, 2.4 +/- 0.7 vs 1.6 +/- 0.4 [P < .001]; vortex pulsation correlation, 1.2 +/- 0.5 vs 0.7 +/- 0.2 [P < .001]).
Echocardiographic particle image velocimetry is feasible. It clearly distinguishes flow patterns in healthy hearts from those in hearts with different types of prosthetic valves. Echocardiographic particle image velocimetry offers new insights into cardiac function and might be of importance to optimize valve replacement therapy.
超声心动图粒子图像测速是一种新的基于特征跟踪的方法，可用于活体可视化和量化左心室流场。我们通过评估健康左心室中的涡流形成以及不同类型的人工瓣膜对心室内流动模式和流介导能量耗散的影响，研究了这项新技术的潜在作用。
我们检查了 19 名患者（平均年龄 57 +/- 19 岁；10 名女性）。9 名健康，10 名患有人工二尖瓣瓣膜（5 名双叶瓣，4 名生物瓣，1 名倾斜碟瓣）。通过静脉内给予左心造影剂进行检查。使用原型软件对心尖超声图像进行离线分析，该软件允许探索心腔内的流动，并通过粒子图像测速法计算能量耗散（相对脉动涡度强度和涡旋脉动相关）。
在健康心脏中，充满整个心室的涡流储存血液的动能，并将血液平稳地重新引导至流出道。在患有人工瓣膜的患者中，根据瓣膜的类型、方向和位置以及左心室几何形状，确定了完全不同的流动模式。与健康受试者相比，患有人工瓣膜的患者的左心室能量耗散明显更高（相对脉动涡度强度，2.4 +/- 0.7 对 1.6 +/- 0.4 [P <.001]；涡旋脉动相关，1.2 +/- 0.5 对 0.7 +/- 0.2 [P <.001]）。
超声心动图粒子图像测速是可行的。它清楚地区分了健康心脏和不同类型人工瓣膜心脏的流动模式。超声心动图粒子图像测速为心脏功能提供了新的见解，可能对优化瓣膜置换治疗具有重要意义。
