Heart and Vascular Institute, Cleveland Clinic J1-5, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
Heart. 2012 Sep;98(17):1311-7. doi: 10.1136/heartjnl-2012-302007. Epub 2012 Jul 3.
Left atrial (LA) function is an important contributor to cardiac function in a variety of disease states and especially with exercise. The purpose of this study was to assess the role of LA function in the left ventricular (LV) filling pressure (E/e') response to exercise and exercise tolerance in patients with preserved LV ejection fraction (LVEF).
LA contractile function (LA strain peak negative), conduit function (LA strain peak positive), and reservoir function (LA strain total) were measured from speckle tracking in 486 patients with preserved LVEF and negative exercise echocardiography for ischaemia. Maximal exercise tolerance was expressed as the estimated metabolic equivalents (METs). Per cent predicted METs was calculated in accordance with described nomograms. Features associated with exercise capacity were sought in a multiple linear regression, and compared using standardised β.
Patients with increased stress E/e' had significantly lower LA strain profiles and larger LA volume than the remainder. LA strain total was strongly associated with exercise capacity in multivariate analysis (ß=0.21, p<0.001). E/e' rest was also associated with exercise capacity (ß=-0.11, p=0.001). Other independent correlates of exercise capacity were age (ß=-0.36, p<0.001), male gender (ß=0.34, p<0.001) and body mass index (ß=-0.23, p<0.001). The best predictor of per cent predicted METs was total LA strain in multivariate analysis.
The association of reduced LA function with impaired exercise capacity was similar to that of elevated LVE/e', emphasising the role of ventriculo-atrial coupling to cardiac dysfunction with preserved LVEF.
左心房（LA）功能是多种疾病状态下心脏功能的重要贡献者，尤其是在运动时。本研究的目的是评估 LA 功能在保留左心室（LV）射血分数（LVEF）患者的 LV 充盈压（E/e'）对运动的反应和运动耐量中的作用。
从斑点追踪技术测量 486 例保留 LVEF 和运动超声心动图阴性缺血的患者的 LA 收缩功能（LA 应变峰值负值）、管道功能（LA 应变峰值正值）和储备功能（LA 应变总）。最大运动耐量表示为估计代谢当量（METs）。按照描述的列线图计算预测 MET 的百分比。在多元线性回归中寻找与运动能力相关的特征，并使用标准化β进行比较。
应激 E/e'增加的患者 LA 应变曲线明显较低，LA 容积较大。多变量分析中 LA 应变总与运动能力密切相关（β=0.21，p<0.001）。E/e'静息也与运动能力相关（β=-0.11，p=0.001）。运动能力的其他独立相关因素是年龄（β=-0.36，p<0.001）、男性性别（β=0.34，p<0.001）和体重指数（β=-0.23，p<0.001）。多元分析中预测预测 METs 的最佳指标是 LA 总应变。
LA 功能降低与运动能力受损的相关性与升高的 LVE/e'相似，强调了心室-心房耦联在保留 LVEF 的情况下对心脏功能障碍的作用。
