Department of Cardiology, Hospital General Universitario Gregorio Marañón, Facultad de Medicina, Universidad Complutense de Madrid, and Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain;
Am J Physiol Heart Circ Physiol. 2014 Mar 1;306(5):H718-29. doi: 10.1152/ajpheart.00697.2013. Epub 2014 Jan 10.
Vortices may have a role in optimizing the mechanical efficiency and blood mixing of the left ventricle (LV). We aimed to characterize the size, position, circulation, and kinetic energy (KE) of LV main vortex cores in patients with nonischemic dilated cardiomyopathy (NIDCM) and analyze their physiological correlates. We used digital processing of color-Doppler images to study flow evolution in 61 patients with NIDCM and 61 age-matched control subjects. Vortex features showed a characteristic biphasic temporal course during diastole. Because late filling contributed significantly to flow entrainment, vortex KE reached its maximum at the time of the peak A wave, storing 26 ± 20% of total KE delivered by inflow (range: 1-74%). Patients with NIDCM showed larger and stronger vortices than control subjects (circulation: 0.008 ± 0.007 vs. 0.006 ± 0.005 m(2)/s, respectively, P = 0.02; KE: 7 ± 8 vs. 5 ± 5 mJ/m, P = 0.04), even when corrected for LV size. This helped confining the filling jet in the dilated ventricle. The vortex Reynolds number was also higher in the NIDCM group. By multivariate analysis, vortex KE was related to the KE generated by inflow and to chamber short-axis diameter. In 21 patients studied head to head, Doppler measurements of circulation and KE closely correlated with phase-contract magnetic resonance values (intraclass correlation coefficient = 0.82 and 0.76, respectively). Thus, the biphasic nature of filling determines normal vortex physiology. Vortex formation is exaggerated in patients with NIDCM due to chamber remodeling, and enlarged vortices are helpful for ameliorating convective pressure losses and facilitating transport. These findings can be accurately studied using ultrasound.
涡旋可能在优化左心室（LV）的机械效率和血液混合方面发挥作用。我们旨在描述非缺血性扩张型心肌病（NIDCM）患者 LV 主涡核的大小、位置、循环和动能（KE），并分析其生理相关性。我们使用彩色多普勒图像的数字处理来研究 61 例 NIDCM 患者和 61 名年龄匹配的对照者的血流演变。涡旋特征在舒张期表现出特征性的双相时程。由于晚期充盈对血流卷入的贡献很大，因此涡旋 KE 在 A 波峰值时达到最大值，储存了流入（范围：1-74%）所传递的总 KE 的 26±20%。NIDCM 患者的涡旋比对照组大且强（循环：分别为 0.008±0.007 与 0.006±0.005 m2/s，P=0.02；KE：7±8 与 5±5 mJ/m，P=0.04），即使校正 LV 大小后也是如此。这有助于将充盈射流限制在扩张的心室中。NIDCM 组的涡旋雷诺数也较高。通过多元分析，涡旋 KE 与流入产生的 KE 和腔室短轴直径相关。在 21 例患者的对头研究中，循环和 KE 的多普勒测量值与相位对比磁共振值密切相关（组内相关系数分别为 0.82 和 0.76）。因此，充盈的双相性质决定了正常的涡旋生理学。由于室重构，NIDCM 患者的涡旋形成被夸大，而扩大的涡旋有助于改善对流压力损失并促进运输。这些发现可以使用超声准确地研究。
