Objectives: Early detection of asymptomatic diastolic dysfunction is essential to prevent the development of heart failure in hypertensive patients. Current studies suggest that left atrial strain contributes to the evaluation of left ventricular diastolic function, but there are fewer studies on the correlation between left atrial strain and diastolic function in hypertensive patients. In this study, we applied a two-dimensional speckle tracking technique to evaluate the changes in left atrial strain in hypertensive patients, and to investigate the relationship between left atrial strain and left ventricular diastolic function.
Methods: A total of 82 hypertensive patients who were visited the Department of Cardiology at the Third Xiangya Hospital of Central South University from July 2021 to January 2022, were enrolled for this study, and 59 healthy subjects served as a control group. According to the number of left ventricular diastolic function indexes recommended by the 2016 American Society of Echocardiography Diastolic Function Guidelines (mitral annular e´ velocity: Septal e´<7 cm/s, lateral e´<10 cm/s, E/e´ ratio>14, left atrial volume index>34 mL/m2, peak tricuspid regurgitation velocity>2.8 m/s), the hypertensive patients were divided into 3 groups: Group Ⅰ (0 index, n=36 ), Group Ⅱ (1 index, n=39), and Group Ⅲ (2 indexes, n=7). Two-dimensional speckle tracking technique was used to measure left atrial reservoir strain (LASr), conduit strain, and contraction strain, and to analyze the correlation between left atrial strain and left ventricular diastolic function in hypertensive patients.
Results: The LASr, left atrial conduit strain (LAScd), and LASr/(E/septal e´) of the hypertension group were lower than those of the control group, and E/LASr was higher than that of the control group. There was no significant difference in left atrium volume index between the 2 groups (P>0.05). Compared with Group Ⅰ, LASr, LAScd, and LASr/(E/septal e´) were decreased in Group Ⅱ and Group Ⅲ, LASr/(E/septal e´) was also decreased in Group Ⅲ compared with Group Ⅱ (all P<0.05). Compared with Group Ⅰ, E/LASr was increased in Group Ⅲ. LASr was positively correlated with septal e´, lateral e´, E, and E/A, and negatively correlated with E/septal e´.
Conclusions: The changes of left atrial function in patients with early hypertension are earlier than those of left atrial structure. Left atrial strain and its combination with conventional ultrasonographic indices [LASr/(E/septal e´)] of diastolic function are potentially useful in assessing left ventricular diastolic function in hypertensive patients.
目的: 早期发现无症状的舒张功能障碍对于防止高血压患者发生心力衰竭至关重要，目前的研究表明左房应变(left atrial strain，LAS)有助于左室舒张功能的评价，但关于高血压患者LAS与舒张功能的相关性研究相对较少。本研究应用二维斑点追踪技术评价高血压患者LAS的变化，并探讨LAS与高血压患者左室舒张功能的关系。方法: 选取2021年7月至2022年1月于中南大学湘雅三医院心内科门诊就诊的高血压患者82例(高血压组)及健康对照者59例(对照组)，根据2016年美国超声心动图学会舒张功能指南中推荐的评价左室舒张功能障碍的指标[二尖瓣环室间隔的血流速度(e´间)<7 cm/s，侧壁的血流速度(e´侧)<10 cm/s，二尖瓣血流E峰血流速度(E)/e´>14，左房容积指数> 34 mL/m2，三尖瓣反流速度>2.8 m/s]个数，将高血压患者分成3组，分别为Ⅰ组(0个指标，n=36)、Ⅱ组(1个指标，n=39)、Ⅲ组(2个指标，n=7)。采用二维斑点追踪技术测量左房储器应变(left atrial reservoir strain，LASr)、左房导管应变(left atrial conduit strain，LAScd)及左房收缩应变(left atrial contraction strain，LASct)，并分析LAS与高血压患者左室舒张功能的相关性。结果: 高血压组LASr、LAScd、LASr/(E/e´间)低于对照组，E/LASr高于对照组(均P<0.05)，2组左心室容积指数无明显差异(P>0.05)。与Ⅰ组比较，Ⅱ组和Ⅲ组LASr、LAScd、LASr/(E/e´间)降低，Ⅲ组E/LASr升高(均P<0.05)。与Ⅱ组比较，Ⅲ组LASr/(E/e´间)下降(P<0.05)。LASr与e´间、e´侧、E及E/二尖瓣血流A峰血流速度(A)呈正相关，与E/e´间呈负相关。结论: 高血压早期患者的左房功能变化早于左房结构改变，LAS及其与常规舒张功能超声指标[LASr/(E/e´间)]结合在评估高血压患者左室舒张功能方面具有潜在的应用价值。.
Keywords: hypertension; left atrial strain; left ventricular diastolic function; speckle tracking imaging.