血流向量成像技术评估心房颤动患者窦性心律下左心室能量损耗

目的 采用血流向量成像技术（VFM）定量评估心房颤动（AF）患者窦性心律下左心室血流能量损耗（EL）。方法 对54例AF患者（AF组）及29名健康志愿者（对照组）行VFM检查，分析等容收缩期（T1）、收缩早期（T2）、收缩晚期（T3）、舒张早期（T4）和心房收缩期（T5）左心室基底段、中间段和心尖段EL，比较2组一般资料、心功能参数以及EL的差异。以与对照组相比5个时相均有统计学意义的EL为应变量、一般资料和心功能参数为自变量，采用多元逐步回归分析各时相EL增高的危险因素。结果 AF组体表面积、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心房最大容积指数（LAVI_max）、二尖瓣舒张早期血流峰值（E）/心房收缩期血流峰值（A）及E/二尖瓣环运动速度（e''）均高于对照组，而A和e''低于对照组（P均<0.05）。各时相基底段EL及T4中间段、心尖段EL，T1、T2心尖段EL明显增高（P均<0.05）；其他时相各节段差异均无统计学意义（P均>0.05）。各时相基底段EL增高的危险因素分别为T1：年龄、E/A；T2：LVESV；T3：LVESV；T4：E/A、E、e''；T5：A、年龄。结论 AF可致左心室各时相基底段EL增高；采用VFM技术定量评估AF患者左心室EL，为观察AF对左心室血流模式的影响提供了新的思路。

Vector flow mapping in quantitative evaluation on left ventricular energy loss in patients with atrial fibrillation in sinus rhythm

Objective To assess the left ventricular flow energy loss (EL) in patients with atrial fibrillation (AF) in sinus rhythm with vector flow mapping (VFM). Methods Totally 54 patients with AF (AF group) and 29 healthy volunteers (control group) underwent VFM inspection. VFM workstation was used to analyze EL at the basal, middle and apical levels of left ventricular at isovolumic contraction phase (T1), early systolic phase (T2), late systolic phase (T3), early diastolic phase (T4) and atrial systolic phase (T5). The differences of general information, cardiac function parameters and EL were compared between the two groups. Taken statistically different EL values compared with control group at 5 phases as dependent variables, indexes with general information and cardiac function parameters as independent variables, multivariate stepwise regression analysis was performed to analyze the risk factors of increased EL at 5 phases. Results In AF group, body surface area, left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), maximal left atrial volume index (LAVI_max), early peak blood flow in mitral valve (E)/atrial systolic blood flow peak (A) and E/mitral annulus movement speed (e'') were higher than those in control group, while A and e'' were lower than those in the control group (all P<0.05). EL at basal level of each phase, the middle and apical levels of T4, apical level of T1 and T2 increased significantly (all P<0.05). There was no significant difference of EL at other phases nor levels (all P>0.05). The risk factors for increased EL in each phase were as follows:T1, age, E/A; T2, LVESV; T3, LVESV; T4, E/A, E, e''; T5, A, age. Conclusion AF can increase EL at basal level in every phase of left ventricum. VFM can quantitatively evaluate the left ventricular EL in patients with AF, therefore providing a new way to observe the impact of AF on blood flow pattern of left ventricum.