Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
Cardiology. 2023;148(5):418-426. doi: 10.1159/000532071. Epub 2023 Jul 28.
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.
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.
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'.
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.
由于心脏周期长度不规则，心房颤动 (AF) 期间舒张功能的超声心动图评估仍然具有挑战性。我们试图评估指数节拍法（即跟随两个先前相等持续时间的心脏周期的节拍）是否可以比连续节拍的常规平均值更可靠地测量 E/e'（二尖瓣 E 波/舒张组织多普勒速度），从而有助于在患有 AF 的患者中无创估计升高的左心房压 (LAP)。
我们前瞻性研究了 35 名持续 AF 且左心室射血分数保留的患者，他们接受了射频消融。在导管消融过程中，通过经房间隔穿刺测量 LAP。在消融前 24 小时进行超声心动图检查，并使用推荐的 10 次节拍平均值和指数节拍法确定 E/e'，观察者对临床细节和 LAP 测量值不知情。
相关性分析显示，两种方法在间隔 E/e'（r = 0.841，p < 0.001）和侧壁 E/e'（r = 0.930，p < 0.001）方面均显示出强烈的正相关。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。使用常规平均值和指数节拍法确定的 E/e'与 LAP 显著相关（p < 0.05）。经过 Fisher Z 变换后，我们发现指数节拍法的间隔 E/e'与 LAP 的相关性优于常规平均值 E/e'（r = 0.736 与 r = 0.392，Zr = -2.110，p = 0.035）。此外，指数节拍法测量 E/e'的时间明显短于常规平均值法（平均 33.6 s；95%置信区间 [CI]：32.1 s-36.2 s）（平均 96.2 s；95%CI：90.2 s-102.3 s；p < 0.001）。受试者工作特征曲线分析显示，预测平均 LAP >12 mm Hg 的最佳截断值为 11（指数节拍法间隔 E/e'的灵敏度为 100%；特异性为 77.3%），而指数节拍法间隔 E/e'为 16（指数节拍法间隔 E/e'的灵敏度为 61.5%；特异性为 95.5%）。
在 AF 患者中，E/e'与 LAP 之间存在良好的相关性，特别是与指数节拍法。此外，指数节拍法可以轻松准确地测量 E/e'，与连续节拍的常规平均值相似，因此可用于评估舒张功能障碍，并可能改善 AF 患者心力衰竭的诊断。
