Koffas H, Dukes-McEwan J, Corcoran B M, Moran C M, French A, Sboros V, Anderson T, Smith P, Simpson K, McDicken W N
Department of Veterinary Clinical Studies, University of Edinburgh, Scotland, UK.
J Vet Intern Med. 2003 Jul-Aug;17(4):510-24. doi: 10.1111/j.1939-1676.2003.tb02472.x.
We sought to assess the feasibility of recording the myocardial velocity gradients (MVGs) and mean myocardial velocities (MMVs) measured by color M-mode tissue Doppler imaging (TDI) in the free wall of unsedated normal cats (n = 18) with a 7.4-MHz probe equipped to record TDI images. The peak MVG and MMV values during the different phases of the cardiac cycle corresponded to certain color velocity patterns occurring in the left ventricular free wall (LVFW). Biphasic shifts were recorded in the tracings of both the MVG and MMV during early diastole (E1 and E2) as well as during the isovolumic relaxation (IVR) and isovolumic contraction (IVC) phases. Stepwise regression analysis showed that age was the only significant predictor for the peak MVG values during the 2nd phase of early diastole (E2) (r = -0.79, r2 = 0.63, and P < .001). The peak late diastolic MVG values were associated positively with age (r = 0.50, r2 = 0.25, and P < .05). The peak MMV values showed a negative association with age during E2 (r = -0.71, r2 = 0.50, and P < .001) as well as during early systole (Se) (r = -0.55, r2 = 0.30, and P < .05) and late systole (SI) (r = -0.62, r2 = 0.39, and P < .01). A positive association was found between age and the peak MMV values during late diastole (r = 0.54, r2 =- 0.29, and P < .05). The MVG values showed cyclic variations consistent with wall thickness changes. The accuracy of velocity determination and the spatial resolution of the system used were validated with a phantom. To our knowledge, this study is the 1st report of the application of this technique to the myocardium of cats,providing insights into the physiology of myocardial motion. It provides reference ranges of the peak MVG and MMV values for future studies of feline myocardial diseases.
我们试图评估使用配备记录组织多普勒成像（TDI）图像的7.4MHz探头，在未镇静的正常猫（n = 18）的游离壁上记录通过彩色M型组织多普勒成像（TDI）测量的心肌速度梯度（MVG）和平均心肌速度（MMV）的可行性。心动周期不同阶段的MVG和MMV峰值对应于左心室游离壁（LVFW）中出现的特定彩色速度模式。在舒张早期（E1和E2）以及等容舒张期（IVR）和等容收缩期（IVC），MVG和MMV的描记中均记录到双相变化。逐步回归分析表明，年龄是舒张早期第二阶段（E2）MVG峰值的唯一显著预测因素（r = -0.79，r2 = 0.63，P <.001）。舒张晚期MVG峰值与年龄呈正相关（r = 0.50，r2 = 0.25，P <.05）。MMV峰值在E2期间（r = -0.71，r2 = 0.50，P <.001）以及收缩早期（Se）（r = -0.55，r2 = 0.30，P <.05）和收缩晚期（SI）（r = -0.62，r2 = 0.39，P <.01）与年龄呈负相关。在舒张晚期，年龄与MMV峰值之间呈正相关（r = 0.54，r2 = 0.29，P <.05）。MVG值显示出与壁厚变化一致的周期性变化。使用体模验证了所使用系统的速度测定准确性和空间分辨率。据我们所知，本研究是该技术应用于猫心肌的首次报告，为心肌运动生理学提供了见解。它为未来猫心肌疾病的研究提供了MVG和MMV峰值的参考范围。
