应变／应变率成像定量评价高血压病合并阵发性心房颤动患者左心房功能的临床研究

Noninvasive functional evaluation of the left atrium in hypertensive patients with paroxysmal atrial fibrillation by strain rate imaging

目的 运用应变／应变率成像技术评价高血压病合并心房颤动（房颤）时心房肌的收缩舒张特性，探讨高血压病和房性心律失常特别是阵发性房颤对心房肌收缩舒张特性的影响。方法 32例健康志愿者和110例高血压病患者被纳入研究，分为4组：对照组（A组），单纯高血压病组（B组），高血压病合并短阵房性心动过速组（C组），高血压病合并阵发性房颤组（D组）。所有研究对象均进行超声心动图和应变／应变率成像检查。结果 与A组相比，D组心率校正的舒张晚期应变率达峰时间、舒张早期应变率差值（AESR）、舒张晚期应变率差值（AASR）和心率校正的舒张晚期应变率达峰时间差值（ATASRc）的差异具有统计学意义。与B组相比，D组的收缩期应变率（SSR）、△ASR、△TASRc、△ESR的差异具有统计学意义。结论 高血压病合并阵发性房颤时，左心房心肌储存器功能受损表现为储存血液势能的能力不变，而效率下降；阵发性房颤损伤了高血压病患者心房肌的传导性，降低了左心房整体的助力泵功能，同时增加了左心房行使管道功能的时间。应变率指标能够无创性定量评价高血压病合并阵发性房颤患者左心房的功能异常。

Objective Strain rate （SR） imaging has been applied to detect regional left ventricular dysfunction but not as much to the assessment of left atrial function. This study was aimed to assess atrial myocardial properties during atrial fibrillation （AF） by strain and SR,focusing on the effects of hypertension and atrial arrhythmias,especially paroxysmal AF. Methods Three groups of a total of 110 consecutive patients with hypertension presenting to our institution was compared： 20 with brief atrial tachycardia,20 with paroxysmal AF, and 70 with hypertension alone. These patients and 32 controls underwent transthoracic echocardiography,strain examination and SR imaging. Atrial strain and SR values of hypertensive patients were compared with those of age-matched controls. Results Compared with controls, hypertensive patients with paroxysmal AF showed significandy increased time to peak late diastolic SR corrected for heart rate （TASRc） and the difference of early diastolic SR （ P 〈 0. 05 for both ）, but significantly decreased difference of late diastolic SR （AASR） （ P 〈 0. 05 ） and the difference of TASRc （ ATASRc ） （ P 〈 0. 001 ）. Moreover, in hypertensive patients with paroxysmal AF,systolic SR （SSR） ,△ASR,and △TASRc were significantly decreased （P 〈0. 05 ,P〈0. 01 ,and P 〈0. 001 ,respectively） ,with △ESR significantly increased （P 〈0.01 ） as compared with hypertensive patients without arrhythmia. Conclusions In hypertensive patients,paroxysmal AF decreases the efficiency, not the ability,of left atrial myocardia to reserve potential energy, which suggests that left atrial myocardial reservoir function decreases. The conductivity of the left atrium is impaired by paroxysmal AF,which leads to decreased total active atrial contraction and prolonged inter-atrial conduction. Noninvasive quantification of left atrial function by SR imaging enables evaluation of left atrial dysfunction due to hypertension and paroxysmal AF.