Miller Brian Edward, López-Candales Angel
Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Department of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Heart Views. 2016 Jan-Mar;17(1):1-6. doi: 10.4103/1995-705X.182647.
The ischemic cascade has long been known to begin with diastolic dysfunction before detectable systolic abnormalities. The advent of speckle-tracking imaging and velocity vector imaging (VVI) has provided accurate and reproducible interpretation of systolic abnormalities in numerous disease processes; however, this imaging tool has been only recently been proposed for detecting diastolic abnormalities.
We analyzed pre and poststress echocardiography images of ten patients using VVI. We calculated normalized strain time (NST) as the duration strain was at least 90% of the measured peak and subtracted pre and poststress NST to calculate prolongation of NST as a sign of diastolic dysfunction. These intervals were measured from left ventricular longitudinal cine images obtained from two and 4-chamber in five patients not only with a positive stress echocardiographic response but also anatomy confirmed by coronary angiography. They were then compared to five patients without coronary artery disease (CAD).
Differences in pre and poststress NST measured in the apical 4-chamber view were greater in CAD patients than without (40 ± 16 vs. 12 ± 19; P = 0.04).
Significant diastolic abnormalities were detected using a semi-automated VVI analysis in the poststress recovery period. A prospective study is now required in a larger number of patients to correlate the development of diastolic strain abnormalities with extent and location of CAD.
长期以来，人们已知缺血级联反应始于舒张功能障碍，之后才出现可检测到的收缩功能异常。斑点追踪成像和速度向量成像（VVI）的出现，为众多疾病过程中的收缩功能异常提供了准确且可重复的解读；然而，这种成像工具直到最近才被用于检测舒张功能异常。
我们使用VVI分析了10例患者的负荷前后超声心动图图像。我们将标准化应变时间（NST）计算为应变持续时间至少为测量峰值的90%时的时间，并计算负荷前后NST的差值，以计算NST延长作为舒张功能障碍的标志。这些时间间隔是从5例不仅负荷超声心动图反应阳性且冠状动脉造影证实解剖结构的患者的左心室纵向电影图像中测量的，这些图像取自两腔心和四腔心切面。然后将其与5例无冠状动脉疾病（CAD）的患者进行比较。
在心尖四腔心切面测量的负荷前后NST差异，CAD患者比无CAD患者更大（40±16 vs. 12±19；P = 0.04）。
在负荷后恢复期使用半自动VVI分析检测到了明显的舒张功能异常。现在需要对更多患者进行前瞻性研究，以将舒张应变异常的发展与CAD的范围和位置相关联。
