应变率显像评价高血压病左心房功能的研究

Noninvasive functional evaluation of the left atrium in hypertensive patients by strain rate imaging

目的运用应变率成像探讨高血压病时左心室肥厚对心房肌收缩、舒张特性的影响。方法56例高血压病患者分为2个亚组：左室心肌质量指数（LVMI）正常组与左心室肥厚组。20例健康志愿者作为对照组。所有研究对象均进行常规超声心动图和应变率成像检查。记录左心房的应变（S）、应变达峰时间（TS）、收缩期应变率峰值（SSR）、舒张早期应变率峰值（ESR）、舒张晚期应变率峰值（ASR）、舒张晚期应变率达峰时间（TASR）以及舒张晚期应变率达峰时间心率校正值（TASRc）。多组间参数比较采用单因素方差分析（one way ANOVA）。结果与对照组相比，高血压病组的ESR显著降低（P〈0．01～0．001），高血压病LVMI正常组的TASRc显著延长（P〈0．05）。与高血压病LVMI正常组相比，高血压病左心室肥厚组的ASR显著降低（P〈0．05）。结论高血压病患者左心房代偿性增大，左心房储存器功能因此增强；高血压病患者左心房的管道功能降低；高血压病左心室肥厚时，左心房助力泵功能降低；应变率指标能无创性定量评价高血压病患者左心房的功能异常。

Objective To investigate the effects of hypertension on left atrial myocardial properties by strain and strain rate（SR） imaging. Methods A total of 56 consecutive patients with hypertension were divided into 2 groups： 33 with normal LVMI and 23 with left ventricular hypertrophy. These patients and 20 controls underwent transthoracic echocardiography, strain and SR imaging examination. Atrial strain and SR values of hypertensive patients were compared with those of controls. Results When compared with the controls, early diastolic SR（ESR） was significantly decreased in hypertensive patients （ P 〈0.01-0. 001 ）, with time to peak late diastolic SR corrected for heart rate（TASRc） significantly increased in normal LVMI subgroup （P 〈0.05）. Moreover, late diastolic SR （ASR） were significantly decreased （P 〈0.05） in hypertensive patients with left ventricular hypertrophy as compared with normal LVMI. Conclusions Enlargement of left atrium leads to increased reservoir function in hypertensive patients, which compensates for the deterioration of conduit function. The duration of atrial systole may be prolonged to meet the need of ventricular filling in consequence of lower left atrial booster pump function. Noninvasive quantification of left atrial function by SR imaging enables evaluation of left atrial dysfunction due to hypertension.