Department of Cardiovascular Diseases, University of Siena, Siena, Italy.
Int J Cardiovasc Imaging. 2012 Oct;28(7):1663-70. doi: 10.1007/s10554-011-9987-y. Epub 2011 Dec 1.
The occurrence of atrial fibrillation (AF), especially in patients with mitral regurgitation (MR), is related to the degree of left atrial (LA) myopathy, remodeling and fibrosis, that are responsible of LA electrical inhomogeneity and abnormal conduction velocities. Speckle tracking echocardiography (STE) has recently enabled the quantification of longitudinal myocardial LA deformation dynamics. Our aim was to investigate by STE the effects of the occurrence of paroxysmal AF on LA myocardial deformation, in a population of patients with asymptomatic chronic MR. We compared two groups of a total of 197 patients with MR: 54 with history of paroxysmal AF and 143 with MR alone. Subgroups were created according to MR degree. Peak atrial longitudinal strain (PALS) was measured in all subjects. Values were obtained by averaging all segments (global PALS), measured in the 4-chamber and 2-chamber views. Compared to the mild MR group (46.1 ± 4.9%), global PALS was lower in moderate MR group (22.1 ± 5.8%) and further reduced in the severe MR group (13.9 ± 4.2%; overall P < 0.0001 by ANOVA, P < 0.05 for all pair-wise comparisons). Besides, in each MR group, patients with history of paroxysmal AF presented a global PALS significantly reduced (overall P < 0.0001 by ANOVA). After multivariate analysis, global PALS was significantly and independently associated with paroxysmal AF. STE enables noninvasive quantification of LA dysfunction due to MR and paroxysmal AF. MR have a major negative impact on LA function. In patients with MR, the history of paroxysmal AF is associated to a further impair of LA myocardial reservoir function.
心房颤动（AF）的发生，尤其是在二尖瓣反流（MR）患者中，与左心房（LA）肌病、重构和纤维化的程度有关，这些因素导致 LA 电异质性和异常传导速度。斑点追踪超声心动图（STE）最近能够定量分析 LA 变形的纵向心肌动力学。我们的目的是通过 STE 研究阵发性 AF 对 LA 心肌变形的影响，研究对象为无症状慢性 MR 患者人群。我们比较了两组共 197 例 MR 患者：54 例有阵发性 AF 病史，143 例单纯 MR。根据 MR 程度创建了亚组。在所有受试者中测量峰值心房纵向应变（PALS）。通过在 4 腔和 2 腔视图中测量所有节段（整体 PALS）来获得值。与轻度 MR 组（46.1±4.9%）相比，中度 MR 组的整体 PALS 较低（22.1±5.8%），重度 MR 组进一步降低（13.9±4.2%；总体通过 ANOVA 分析 P<0.0001，所有两两比较 P<0.05）。此外，在每个 MR 组中，有阵发性 AF 病史的患者整体 PALS 明显降低（总体通过 ANOVA 分析 P<0.0001）。多变量分析后，整体 PALS 与阵发性 AF 显著相关。STE 能够无创定量分析因 MR 和阵发性 AF 导致的 LA 功能障碍。MR 对 LA 功能有重大负面影响。在 MR 患者中，阵发性 AF 病史与 LA 心肌储备功能进一步受损相关。
