Lin Mingjie, Hao Li, Cao Yuan, Zhao Yachao, Rong Bing, Han Wenqiang, Xie Fei, Zhong Jingquan
The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China.
Echocardiography. 2019 Apr;36(4):752-760. doi: 10.1111/echo.14304. Epub 2019 Mar 9.
Dissipative energy loss (EL), a new index to quantify the inefficient blood flow, has not been explored within left atrium (LA) in patients with atrial fibrillation (AF). We aimed to study the intra-atrial flow and mechanics in patients with AF before and after successful catheter ablation by evaluating EL and LA global longitudinal strain (LAS).
In our study, there were 53 patients undergoing catheter ablation for AF at baseline (AF group) and 33 age- and sex-matched controls. They were both assessed of LA EL using vector flow mapping (VFM) and of LAS using two-dimensional tracking (2DTT) during systole (sys), early diastole (ed), and atrial contraction phase (ac). Out of 53 patients, 37 patients who sustained sinus rhythm and carried out the echocardiographic examination at 3 and 6 months follow-up were evaluated of change in EL and LAS. The independent predictors of EL during three phases in AF group were performed using stepwise multivariate linear regression analyses.
Left atrium EL and LAS among all phases in AF group were significantly lower than controls (all P < 0.01). During follow-up, LASsys and LASac both significantly improved at 3 and 6 months (both P < 0.01), and ELac significantly increased after 6 months (P < 0.05); ELsys, ELed and LASed were no significant change; EL and LAS among all phases were no normalized during follow-up. The independent predictors of EL were: for ELsys, BSA (P = 0.004) and LASac (P = 0.025); for ELed, E (P = 0.001) and A (P = 0.014); for ELac, E/A (P < 0.001).
Vector flow mapping and 2DTT revealed impaired intra-atrial flow and mechanics. Successful catheter ablation for AF slightly improves but not reverses the aforementioned impairment, indicating the continuous LA dysfunction.
耗散能量损失（EL）是一种用于量化低效血流的新指标，尚未在心房颤动（AF）患者的左心房（LA）中进行研究。我们旨在通过评估EL和LA整体纵向应变（LAS）来研究AF患者成功导管消融前后的心房内血流和力学情况。
在我们的研究中，有53例基线时接受AF导管消融的患者（AF组）和33例年龄和性别匹配的对照者。在收缩期（sys）、舒张早期（ed）和心房收缩期（ac）期间，使用向量血流图（VFM）评估LA的EL，并使用二维追踪（2DTT）评估LAS。在53例患者中，对37例维持窦性心律并在3个月和6个月随访时进行超声心动图检查的患者评估EL和LAS的变化。使用逐步多元线性回归分析确定AF组三个阶段中EL的独立预测因素。
AF组所有阶段的左心房EL和LAS均显著低于对照组（均P<0.01）。随访期间，LASsys和LASac在3个月和6个月时均显著改善（均P<0.01），ELac在6个月后显著增加（P<0.05）；ELsys、ELed和LASed无显著变化；随访期间所有阶段的EL和LAS均未恢复正常。EL的独立预测因素为：对于ELsys，体表面积（BSA）（P=0.004）和LASac（P=0.025）；对于ELed，E（P=0.001）和A（P=0.014）；对于ELac，E/A（P<0.001）。
向量血流图和2DTT显示心房内血流和力学受损。AF成功导管消融可轻微改善但不能逆转上述损害，表明LA持续功能障碍。
