二维斑点追踪超声评价餐后低血压对左室心肌应变的影响
Evaluation of the effect of postprandial hypotension on left ventricular myocardial strain by 2D speckle tracking imaging

目的 采用二维斑点追踪超声成像（2D-STI）定量评价餐后低血压(PPH)患者左心室心肌应变的早期损害。方法 入选首次诊断PPH患者20例，21例非PPH患者对照。应用2D-STI测定2组餐前及餐后1.5 h左心室整体纵向应变（GLS）、环周应变（GCS）和径向应变（GRS），同时用常规方法测量心脏结构和功能。结果 常规方法检测2组心脏结构功能无显著差异。餐前PPH组GLS显著低于非PPH组（P=0.02）,GCS、GRS无显著差异。对比2组患者餐前、餐后心肌应变，发现PPH组餐后1.5 h GLS（P=0.045）显著下降，而非PPH组餐前餐后整体心肌应变无显著差异。采用Logistic 回归分析，餐前GLS（P=0.02,OR=0.46），餐后GLS（P=0.001，OR=0.27）、GCS（P=0.008，OR=0.41）、GRS（P=0.004，OR=0.33）和PPH具有显著相关性。餐后GLS的ROC曲线下面积（AUC=0.86, P=0.001）显著大于24 h平均SBP（AUC=0.66, P=0.08）和左室射血分数（AUC=0.44, P=0.47）。结论 PPH可能会引起心脏功能隐匿性损害。相比常规心脏超声检查，STI技术能更容易发现PPH左心室心肌功能的早期损害。
： Objective To quantitatively evaluate the early injury in left ventricular myocardial strain in patients with postprandial hypotension (PPH) by using 2D speckle tracking imaging (2D-STI). Methods Twenty patients who were first diagnosed with PPH (PPH group) and 21 patients without PPH (NPPH group) were recruited. The global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) of left ventricle were measured before and 1.5 h after meal with 2D-STI. Meanwhile, cardiac structure and function were evaluated by conventional method. Results There was no significant difference in heart structure evaluated by conventional method between two groups. Before meal, GLS in the PPH group was significantly lower as compared with the NPPH group (P=0.02), but there was no significant difference in GCS and GRS. GLS in the PPH group was significantly decreased 1.5 h after meal as compared with that before meal (P=0.045), whereas there was no significant change in the overall myocardial strain in the NPPH group after meal. Logistic regression analysis showed that GLS before meal (P=0.02,OR=0.46), and GLS (P=0.001, OR=0.27), GCS (P=0.008，OR=0.41), and GRS (P=0.004，OR=0.33) after meal were significantly correlated to PPH. The area under the ROC curve of GLS after meal (AUC=0.86, P=0.001） was significantly greater than 24 h average SBP (AUC=0.66, P=0.08) and LVEF (AUC=0.44, P=0.47). Conclusion PPH may result in occult cardiac function injury. STI is superior to conventional echocardiography in detecting the early injury in left ventricular myocardial function for patients with PPH