INTRODUCTION Echocardiographic assessment of diastolic function during atrial fibrillation (AF) remains challenging due to the irregular cardiac cycle length. We sought to assess whether the index-beat method, the beat following two preceding cardiac cycles of equal duration, could provide a more reliable measurement of E/e' (mitral E wave/diastolic tissue Doppler velocity) than the conventional averaging of consecutive beats and hence facilitate the noninvasive estimation of elevated left atrial pressure (LAP) in patients with AF. METHODS We prospectively studied 35 patients with persistent AF who had preserved left ventricular ejection fraction and underwent radiofrequency ablation. LAP was measured in conjunction with transseptal puncture during catheter ablation. Echocardiography was performed 24 h before ablation and E/e' was determined using the recommended averaging of 10 beats and the index-beat method, with the observers blinded to the clinical details and LAP measurements. RESULTS Correlation analysis showed a strong positive correlation between two methods in terms of both septal E/e' (r = 0.841, p < 0.001) and lateral E/e' (r = 0.930, p < 0.001). Bland-Altman analysis also showed a good agreement between the two measurement methods in terms of E/e'. E/e' determined using both conventional averaging and the index-beat method was significantly correlated with LAP (p < 0.05). After Fisher Z transformation, we found that the index-beat septal E/e' had a better correlation with LAP than did the conventional averaging E/e' (r = 0.736 vs. r = 0.392, Zr = -2.110, p = 0.035). Furthermore, the index-beat method took significantly less time to measure E/e' (mean 33.6 s; 95% confidence intervals [CIs]: 32.1 s-36.2 s) than did conventional averaging method (mean 96.2 s; 95% CI: 90.2 s-102.3 s; p < 0.001). Receiver operating characteristic curve analysis revealed that the optimal cut-off for predicting mean LAP >12 mm Hg was 11 (sensitivity 100%; specificity 77.3%) for index-beat septal E/e' and 16 (sensitivity 61.5%; specificity 95.5%) for index-beat lateral E/e'. CONCLUSIONS Good correlations were found between E/e' and LAP in patients with AF, particularly with the index-beat method. Moreover, the index-beat method can easily measure E/e' at an accuracy similar to that for the conventional averaging of consecutive beats, which can therefore be applied to assess the diastolic dysfunction and potentially improve the diagnosis of heart failure in patients with AF.

中文翻译：

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使用指数搏动方法对 E/e' 进行验证，作为心房颤动患者左心房压力的估计。

简介 由于心动周期长度不规则，超声心动图评估心房颤动 (AF) 期间的舒张功能仍然具有挑战性。我们试图评估指数搏动方法（即前两个相同持续时间的心动周期之后的搏动）是否可以提供比连续搏动的传统平均法更可靠的 E/e'（二尖瓣 E 波/舒张组织多普勒速度）测量从而有助于对 AF 患者升高的左心房压力 (LAP) 进行无创评估。方法 我们前瞻性研究了 35 名保留左心室射血分数并接受射频消融的持续性房颤患者。LAP 是在导管消融过程中与房间隔穿刺结合测量的。消融前 24 小时进行超声心动图检查，并使用推荐的 10 次心跳平均和指数心跳方法确定 E/e'，观察者对临床细节和 LAP 测量不知情。结果 相关性分析显示，两种方法在间隔 E/e' (r = 0.841，p < 0.001) 和侧向 E/e' (r = 0.930，p < 0.001) 方面均呈强正相关。Bland-Altman 分析还表明，两种测量方法在 E/e' 方面具有良好的一致性。使用传统平均法和指数搏动法确定的 E/e' 与 LAP 显着相关 (p < 0.05)。经过Fisher Z变换后，我们发现指数搏动隔膜E/e'与LAP的相关性比传统平均E/e'更好（r = 0.736 vs. r = 0.392，Zr = -2.110，p = 0.035 ）。此外，指数搏动方法测量 E/e' 所需的时间（平均 33.6 秒；95% 置信区间 [CI]：32.1 秒-36.2 秒）比传统平均方法（平均 96.2 秒；95% CI： 90.2 秒-102.3 秒；p < 0.001)。受试者工作特征曲线分析显示，预测平均 LAP >12 mm Hg 的最佳截止点为 11（敏感性 100%；特异性 77.3%），对于指数搏动间隔 E/e' 和 16（敏感性 61.5%；特异性 95.5%） ) 对于指数搏动横向 E/e'。结论 AF 患者的 E/e' 和 LAP 之间存在良好的相关性，尤其是指数搏动法。此外，指数心跳方法可以轻松测量 E/e'，其准确度与传统的连续心跳平均相似，因此可用于评估舒张功能障碍，并有可能改善 AF 患者心力衰竭的诊断。